diff --git a/dedoc/attachments_handler/attachments_handler.py b/dedoc/attachments_handler/attachments_handler.py
index 37f4f98c..9b71a20d 100644
--- a/dedoc/attachments_handler/attachments_handler.py
+++ b/dedoc/attachments_handler/attachments_handler.py
@@ -95,11 +95,10 @@ def _handle_attachments(self, document: UnstructuredDocument, parameters: dict)
             attachment.tmp_file_path = new_path
 
     def __get_empty_document(self, document_parser: "DedocManager", attachment: AttachedFile, parameters: dict) -> ParsedDocument:  # noqa
-        unstructured_document = UnstructuredDocument(lines=[], tables=[], attachments=[])
         attachment_dir, attachment_name = os.path.split(attachment.get_filename_in_path())
-        unstructured_document = document_parser.document_metadata_extractor.add_metadata(document=unstructured_document, directory=attachment_dir,
-                                                                                         filename=attachment_name, converted_filename=attachment_name,
-                                                                                         original_filename=attachment.get_original_filename(),
-                                                                                         parameters=parameters)
-        metadata = DocumentMetadata(**unstructured_document.metadata)
+        metadata = document_parser.document_metadata_extractor.extract_metadata(directory=attachment_dir,
+                                                                                filename=attachment_name, converted_filename=attachment_name,
+                                                                                original_filename=attachment.get_original_filename(),
+                                                                                parameters=parameters)
+        metadata = DocumentMetadata(**metadata)
         return ParsedDocument(content=get_empty_content(), metadata=metadata)
diff --git a/dedoc/dedoc_manager.py b/dedoc/dedoc_manager.py
index ee308f1a..1ee0b947 100644
--- a/dedoc/dedoc_manager.py
+++ b/dedoc/dedoc_manager.py
@@ -103,13 +103,13 @@ def __parse_no_error_handling(self, file_path: str, parameters: Dict[str, str])
             self.logger.info(f"Finish parse file {file_name}")
 
             # Step 3 - Adding meta-information
-            unstructured_document = self.document_metadata_extractor.add_metadata(document=unstructured_document,
-                                                                                  directory=tmp_dir,
-                                                                                  filename=unique_filename,
-                                                                                  converted_filename=converted_filename,
-                                                                                  original_filename=file_name,
-                                                                                  parameters=parameters,
-                                                                                  other_fields=unstructured_document.metadata)
+            metadata = self.document_metadata_extractor.extract_metadata(directory=tmp_dir,
+                                                                         filename=unique_filename,
+                                                                         converted_filename=converted_filename,
+                                                                         original_filename=file_name,
+                                                                         parameters=parameters,
+                                                                         other_fields=unstructured_document.metadata)
+            unstructured_document.metadata = metadata
             self.logger.info(f"Add metadata of file {file_name}")
 
             # Step 4 - Extract structure
diff --git a/dedoc/metadata_extractors/abstract_metadata_extractor.py b/dedoc/metadata_extractors/abstract_metadata_extractor.py
index 6346d155..602ee68e 100644
--- a/dedoc/metadata_extractors/abstract_metadata_extractor.py
+++ b/dedoc/metadata_extractors/abstract_metadata_extractor.py
@@ -1,8 +1,6 @@
 from abc import ABC, abstractmethod
 from typing import Optional
 
-from dedoc.data_structures.unstructured_document import UnstructuredDocument
-
 
 class AbstractMetadataExtractor(ABC):
     """
@@ -10,7 +8,6 @@ class AbstractMetadataExtractor(ABC):
     """
     @abstractmethod
     def can_extract(self,
-                    document: UnstructuredDocument,
                     directory: str,
                     filename: str,
                     converted_filename: str,
@@ -19,30 +16,28 @@ def can_extract(self,
                     other_fields: Optional[dict] = None) -> bool:
         """
         Check if this extractor can handle the given file. Return True if the extractor can handle it and False otherwise.
-        Look to the :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.add_metadata` documentation to get the information about parameters.
+        Look to the :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.extract_metadata` documentation to get the information about parameters.
         """
         pass
 
     @abstractmethod
-    def add_metadata(self,
-                     document: UnstructuredDocument,
-                     directory: str,
-                     filename: str,
-                     converted_filename: str,
-                     original_filename: str,
-                     parameters: Optional[dict] = None,
-                     other_fields: Optional[dict] = None) -> UnstructuredDocument:
+    def extract_metadata(self,
+                         directory: str,
+                         filename: str,
+                         converted_filename: str,
+                         original_filename: str,
+                         parameters: Optional[dict] = None,
+                         other_fields: Optional[dict] = None) -> dict:
         """
-        Add metadata to the document if possible, i.e. method :meth:`can_extract` returned True.
+        Extract metadata from file if possible, i.e. method :meth:`can_extract` returned True.
 
-        :type document: document content that has been received from some of the readers
-        :type directory: path to the directory where the original and converted files are located
-        :type filename: name of the file after renaming (for example 23141.doc). \
+        :param directory: path to the directory where the original and converted files are located
+        :param filename: name of the file after renaming (for example 23141.doc). \
         The file gets a new name during processing by the dedoc manager (if used)
-        :type converted_filename: name of the file after renaming and conversion (for example 23141.docx)
-        :type original_filename: name of the file before renaming
-        :type parameters: additional parameters for document parsing
-        :type other_fields: other fields that should be added to the document's metadata
-        :return: document content with added metadata attribute (dict with information about the document)
+        :param converted_filename: name of the file after renaming and conversion (for example 23141.docx)
+        :param original_filename: name of the file before renaming
+        :param parameters: additional parameters for document parsing
+        :param other_fields: other fields that should be added to the document's metadata
+        :return: dict with metadata information about the document
         """
         pass
diff --git a/dedoc/metadata_extractors/concrete_metadata_extractors/base_metadata_extractor.py b/dedoc/metadata_extractors/concrete_metadata_extractors/base_metadata_extractor.py
index f545ee1e..e685becc 100644
--- a/dedoc/metadata_extractors/concrete_metadata_extractors/base_metadata_extractor.py
+++ b/dedoc/metadata_extractors/concrete_metadata_extractors/base_metadata_extractor.py
@@ -2,7 +2,6 @@
 from base64 import b64encode
 from typing import Optional
 
-from dedoc.data_structures.unstructured_document import UnstructuredDocument
 from dedoc.metadata_extractors.abstract_metadata_extractor import AbstractMetadataExtractor
 from dedoc.utils.utils import get_file_mime_type
 
@@ -22,7 +21,6 @@ class BaseMetadataExtractor(AbstractMetadataExtractor):
     """
 
     def can_extract(self,
-                    document: UnstructuredDocument,
                     directory: str,
                     filename: str,
                     converted_filename: str,
@@ -35,17 +33,16 @@ def can_extract(self,
         """
         return True
 
-    def add_metadata(self,
-                     document: UnstructuredDocument,
-                     directory: str,
-                     filename: str,
-                     converted_filename: str,
-                     original_filename: str,
-                     parameters: Optional[dict] = None,
-                     other_fields: Optional[dict] = None) -> UnstructuredDocument:
+    def extract_metadata(self,
+                         directory: str,
+                         filename: str,
+                         converted_filename: str,
+                         original_filename: str,
+                         parameters: Optional[dict] = None,
+                         other_fields: Optional[dict] = None) -> dict:
         """
         Gets the basic meta-information about the file.
-        Look to the :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.add_metadata` documentation to get the information about parameters.
+        Look to the :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.extract_metadata` documentation to get the information about parameters.
         """
         parameters = {} if parameters is None else parameters
         meta_info = self._get_base_meta_information(directory, filename, original_filename)
@@ -59,8 +56,7 @@ def add_metadata(self,
 
         if other_fields is not None and len(other_fields) > 0:
             meta_info["other_fields"] = other_fields
-        document.metadata = meta_info
-        return document
+        return meta_info
 
     @staticmethod
     def _get_base_meta_information(directory: str, filename: str, name_actual: str) -> dict:
diff --git a/dedoc/metadata_extractors/concrete_metadata_extractors/docx_metadata_extractor.py b/dedoc/metadata_extractors/concrete_metadata_extractors/docx_metadata_extractor.py
index 377cba55..49b87001 100644
--- a/dedoc/metadata_extractors/concrete_metadata_extractors/docx_metadata_extractor.py
+++ b/dedoc/metadata_extractors/concrete_metadata_extractors/docx_metadata_extractor.py
@@ -5,7 +5,6 @@
 import docx
 from docx.opc.exceptions import PackageNotFoundError
 
-from dedoc.data_structures.unstructured_document import UnstructuredDocument
 from dedoc.metadata_extractors.concrete_metadata_extractors.base_metadata_extractor import BaseMetadataExtractor
 
 
@@ -24,7 +23,6 @@ class DocxMetadataExtractor(BaseMetadataExtractor):
         - created, modified and last printed date.
     """
     def can_extract(self,
-                    document: UnstructuredDocument,
                     directory: str,
                     filename: str,
                     converted_filename: str,
@@ -37,27 +35,26 @@ def can_extract(self,
         """
         return converted_filename.lower().endswith("docx")
 
-    def add_metadata(self,
-                     document: UnstructuredDocument,
-                     directory: str,
-                     filename: str,
-                     converted_filename: str,
-                     original_filename: str,
-                     parameters: dict = None,
-                     other_fields: Optional[dict] = None) -> UnstructuredDocument:
+    def extract_metadata(self,
+                         directory: str,
+                         filename: str,
+                         converted_filename: str,
+                         original_filename: str,
+                         parameters: dict = None,
+                         other_fields: Optional[dict] = None) -> dict:
         """
         Add the predefined list of metadata for the docx documents.
-        Look to the :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.add_metadata` documentation to get the information about parameters.
+        Look to the :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.extract_metadata` documentation to get the information about parameters.
         """
         parameters = {} if parameters is None else parameters
 
-        result = super().add_metadata(document=document, directory=directory, filename=filename, converted_filename=converted_filename,
-                                      original_filename=original_filename, parameters=parameters, other_fields=other_fields)
+        result = super().extract_metadata(directory=directory, filename=filename, converted_filename=converted_filename,
+                                          original_filename=original_filename, parameters=parameters, other_fields=other_fields)
 
         file_path = os.path.join(directory, converted_filename)
         docx_other_fields = self._get_docx_fields(file_path)
 
-        result.metadata["other_fields"] = {**result.metadata.get("other_fields", {}), **docx_other_fields}
+        result["other_fields"] = {**result.get("other_fields", {}), **docx_other_fields}
         return result
 
     def __convert_date(self, date: Optional[datetime]) -> Optional[int]:
diff --git a/dedoc/metadata_extractors/concrete_metadata_extractors/image_metadata_extractor.py b/dedoc/metadata_extractors/concrete_metadata_extractors/image_metadata_extractor.py
index ac573d02..31062c72 100644
--- a/dedoc/metadata_extractors/concrete_metadata_extractors/image_metadata_extractor.py
+++ b/dedoc/metadata_extractors/concrete_metadata_extractors/image_metadata_extractor.py
@@ -7,7 +7,6 @@
 from PIL import ExifTags, Image
 from dateutil import parser
 
-from dedoc.data_structures.unstructured_document import UnstructuredDocument
 from dedoc.metadata_extractors.concrete_metadata_extractors.base_metadata_extractor import BaseMetadataExtractor
 
 
@@ -54,7 +53,6 @@ def __init__(self, *, config: dict) -> None:
         }
 
     def can_extract(self,
-                    document: UnstructuredDocument,
                     directory: str,
                     filename: str,
                     converted_filename: str,
@@ -67,25 +65,24 @@ def can_extract(self,
         """
         return filename.lower().endswith((".png", ".jpg", ".jpeg"))
 
-    def add_metadata(self,
-                     document: UnstructuredDocument,
-                     directory: str,
-                     filename: str,
-                     converted_filename: str,
-                     original_filename: str,
-                     parameters: dict = None,
-                     other_fields: Optional[dict] = None) -> UnstructuredDocument:
+    def extract_metadata(self,
+                         directory: str,
+                         filename: str,
+                         converted_filename: str,
+                         original_filename: str,
+                         parameters: dict = None,
+                         other_fields: Optional[dict] = None) -> dict:
         """
         Add the predefined list of metadata for images.
-        Look to the :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.add_metadata` documentation to get the information about parameters.
+        Look to the :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.extract_metadata` documentation to get the information about parameters.
         """
-        result = super().add_metadata(document=document, directory=directory, filename=filename, converted_filename=converted_filename,
-                                      original_filename=original_filename, parameters=parameters, other_fields=other_fields)
+        result = super().extract_metadata(directory=directory, filename=filename, converted_filename=converted_filename,
+                                          original_filename=original_filename, parameters=parameters, other_fields=other_fields)
 
         path = os.path.join(directory, filename)
         exif_fields = self._get_exif(path)
         if len(exif_fields) > 0:
-            result.metadata["other_fields"] = {**result.metadata.get("other_fields", {}), **exif_fields}
+            result["other_fields"] = {**result.get("other_fields", {}), **exif_fields}
         return result
 
     def __encode_exif(self, exif: Union[str, bytes]) -> Optional[str]:
diff --git a/dedoc/metadata_extractors/concrete_metadata_extractors/note_metadata_extarctor.py b/dedoc/metadata_extractors/concrete_metadata_extractors/note_metadata_extarctor.py
index 2708e5e6..18b49d6b 100644
--- a/dedoc/metadata_extractors/concrete_metadata_extractors/note_metadata_extarctor.py
+++ b/dedoc/metadata_extractors/concrete_metadata_extractors/note_metadata_extarctor.py
@@ -3,7 +3,6 @@
 from typing import Optional
 
 from dedoc.common.exceptions.bad_file_error import BadFileFormatError
-from dedoc.data_structures.unstructured_document import UnstructuredDocument
 from dedoc.metadata_extractors.concrete_metadata_extractors.base_metadata_extractor import BaseMetadataExtractor
 
 
@@ -18,7 +17,6 @@ def __init__(self) -> None:
         super().__init__()
 
     def can_extract(self,
-                    document: UnstructuredDocument,
                     directory: str,
                     filename: str,
                     converted_filename: str,
@@ -31,17 +29,16 @@ def can_extract(self,
         """
         return filename.lower().endswith(".note.pickle")
 
-    def add_metadata(self,
-                     document: UnstructuredDocument,
-                     directory: str,
-                     filename: str,
-                     converted_filename: str,
-                     original_filename: str,
-                     parameters: dict = None,
-                     other_fields: Optional[dict] = None) -> UnstructuredDocument:
+    def extract_metadata(self,
+                         directory: str,
+                         filename: str,
+                         converted_filename: str,
+                         original_filename: str,
+                         parameters: dict = None,
+                         other_fields: Optional[dict] = None) -> dict:
         """
         Add the predefined list of metadata for the .note.pickle documents.
-        Look to the :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.add_metadata` documentation to get the information about parameters.
+        Look to the :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.extract_metadata` documentation to get the information about parameters.
         """
 
         try:
@@ -59,7 +56,6 @@ def add_metadata(self,
                              created_time=note_dict["created_time"],
                              modified_time=note_dict["modified_time"],
                              other_fields=other_fields)
-            document.metadata = meta_info
-            return document
+            return meta_info
         except Exception:
             raise BadFileFormatError(f"Bad note file:\n file_name = {os.path.basename(filename)}. Seems note-format is broken")
diff --git a/dedoc/metadata_extractors/concrete_metadata_extractors/pdf_metadata_extractor.py b/dedoc/metadata_extractors/concrete_metadata_extractors/pdf_metadata_extractor.py
index 96682fc0..274a8d26 100644
--- a/dedoc/metadata_extractors/concrete_metadata_extractors/pdf_metadata_extractor.py
+++ b/dedoc/metadata_extractors/concrete_metadata_extractors/pdf_metadata_extractor.py
@@ -5,7 +5,6 @@
 from PyPDF2 import PdfFileReader
 from PyPDF2.utils import PdfReadError
 
-from dedoc.data_structures.unstructured_document import UnstructuredDocument
 from dedoc.metadata_extractors.concrete_metadata_extractors.base_metadata_extractor import BaseMetadataExtractor
 from dedoc.utils.utils import convert_datetime
 
@@ -47,7 +46,6 @@ def __init__(self, *, config: dict) -> None:
         self.logger = config.get("logger", logging.getLogger())
 
     def can_extract(self,
-                    document: UnstructuredDocument,
                     directory: str,
                     filename: str,
                     converted_filename: str,
@@ -60,24 +58,23 @@ def can_extract(self,
         """
         return filename.lower().endswith(".pdf")
 
-    def add_metadata(self,
-                     document: UnstructuredDocument,
-                     directory: str,
-                     filename: str,
-                     converted_filename: str,
-                     original_filename: str,
-                     parameters: dict = None,
-                     other_fields: Optional[dict] = None) -> UnstructuredDocument:
+    def extract_metadata(self,
+                         directory: str,
+                         filename: str,
+                         converted_filename: str,
+                         original_filename: str,
+                         parameters: dict = None,
+                         other_fields: Optional[dict] = None) -> dict:
         """
         Add the predefined list of metadata for the pdf documents.
-        Look to the :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.add_metadata` documentation to get the information about parameters.
+        Look to the :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.extract_metadata` documentation to get the information about parameters.
         """
-        result = super().add_metadata(document=document, directory=directory, filename=filename, converted_filename=converted_filename,
-                                      original_filename=original_filename, parameters=parameters, other_fields=other_fields)
+        result = super().extract_metadata(directory=directory, filename=filename, converted_filename=converted_filename,
+                                          original_filename=original_filename, parameters=parameters, other_fields=other_fields)
         path = os.path.join(directory, filename)
         pdf_fields = self._get_pdf_info(path)
         if len(pdf_fields) > 0:
-            result.metadata["other_fields"] = {**result.metadata.get("other_fields", {}), **pdf_fields}
+            result["other_fields"] = {**result.get("other_fields", {}), **pdf_fields}
         return result
 
     def _get_pdf_info(self, path: str) -> dict:
diff --git a/dedoc/metadata_extractors/metadata_extractor_composition.py b/dedoc/metadata_extractors/metadata_extractor_composition.py
index 68e308c9..e9c182d4 100644
--- a/dedoc/metadata_extractors/metadata_extractor_composition.py
+++ b/dedoc/metadata_extractors/metadata_extractor_composition.py
@@ -1,6 +1,5 @@
 from typing import List, Optional
 
-from dedoc.data_structures.unstructured_document import UnstructuredDocument
 from dedoc.metadata_extractors.abstract_metadata_extractor import AbstractMetadataExtractor
 
 
@@ -13,36 +12,33 @@ class MetadataExtractorComposition:
     """
     def __init__(self, extractors: List[AbstractMetadataExtractor]) -> None:
         """
-        :param extractors: the list of extractors with methods can_extract() and add_metadata() to extract metadata from file
+        :param extractors: the list of extractors with methods can_extract() and extract_metadata() to extract metadata from file
         """
         self.extractors = extractors
 
-    def add_metadata(self,
-                     document: UnstructuredDocument,
-                     directory: str,
-                     filename: str,
-                     converted_filename: str,
-                     original_filename: str,
-                     parameters: Optional[dict] = None,
-                     other_fields: Optional[dict] = None) -> UnstructuredDocument:
+    def extract_metadata(self,
+                         directory: str,
+                         filename: str,
+                         converted_filename: str,
+                         original_filename: str,
+                         parameters: Optional[dict] = None,
+                         other_fields: Optional[dict] = None) -> dict:
         """
-        Add metadata to the document using one of the extractors if suitable extractor was found.
-        Look to the method :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.add_metadata` of the class
+        Extract metadata using one of the extractors if suitable extractor was found.
+        Look to the method :meth:`~dedoc.metadata_extractors.AbstractMetadataExtractor.extract_metadata` of the class
         :class:`~dedoc.metadata_extractors.AbstractMetadataExtractor` documentation to get the information about method's parameters.
         """
         for extractor in self.extractors:
-            if extractor.can_extract(document=document,
-                                     directory=directory,
+            if extractor.can_extract(directory=directory,
                                      filename=filename,
                                      converted_filename=converted_filename,
                                      original_filename=original_filename,
                                      parameters=parameters,
                                      other_fields=other_fields):
-                return extractor.add_metadata(document=document,
-                                              directory=directory,
-                                              filename=filename,
-                                              converted_filename=converted_filename,
-                                              original_filename=original_filename,
-                                              parameters=parameters,
-                                              other_fields=other_fields)
+                return extractor.extract_metadata(directory=directory,
+                                                  filename=filename,
+                                                  converted_filename=converted_filename,
+                                                  original_filename=original_filename,
+                                                  parameters=parameters,
+                                                  other_fields=other_fields)
         raise Exception(f"Can't extract metadata from from file {filename}")
diff --git a/docs/source/_static/code_examples/dedoc_usage_tutorial.py b/docs/source/_static/code_examples/dedoc_usage_tutorial.py
index 52bb29b4..122ea40e 100644
--- a/docs/source/_static/code_examples/dedoc_usage_tutorial.py
+++ b/docs/source/_static/code_examples/dedoc_usage_tutorial.py
@@ -75,8 +75,8 @@
 
 """Using metadata extractors"""
 metadata_extractor = DocxMetadataExtractor()
-metadata_extractor.can_extract(document, file_dir, file_name, file_name, file_name)  # True
-document = metadata_extractor.add_metadata(document, file_dir, file_name, file_name, file_name)
+metadata_extractor.can_extract(file_dir, file_name, file_name, file_name)  # True
+document.metadata = metadata_extractor.extract_metadata(file_dir, file_name, file_name, file_name)
 document.metadata  # {'file_name': 'example.docx', 'file_type': 'application/vnd.openxmlformats-officedocument.wordprocessingml.document', 'size': 373795,
 # 'access_time': 1686825619, 'created_time': 1686825617, 'modified_time': 1686823541, 'other_fields': {'document_subject': '', 'keywords': '',
 # 'category': '', 'comments': '', 'author': '', 'last_modified_by': '', 'created_date': 1568725611, 'modified_date': 1686752726,
diff --git a/docs/source/getting_started/usage.rst b/docs/source/getting_started/usage.rst
index 7eea3c3e..1114cb87 100644
--- a/docs/source/getting_started/usage.rst
+++ b/docs/source/getting_started/usage.rst
@@ -200,7 +200,7 @@ the metadata extractor can extract metadata from the given file:
     :language: python
     :lines: 78
 
-To extract metadata, one can add them to the document using :meth:`~dedoc.metadata_extractors.DocxMetadataExtractor.add_metadata` method.
+To extract metadata, one can add them to the document using :meth:`~dedoc.metadata_extractors.DocxMetadataExtractor.extract_metadata` method.
 
 .. literalinclude:: ../_static/code_examples/dedoc_usage_tutorial.py
     :language: python
diff --git a/examples/create_unstructured_document.py b/examples/create_unstructured_document.py
index 0da38dc9..cf724e1a 100644
--- a/examples/create_unstructured_document.py
+++ b/examples/create_unstructured_document.py
@@ -58,8 +58,5 @@
 # HierarchyLevel(1, 1) for 1.
 # HierarchyLevel(1, 2) for 1.1.
 # HierarchyLevel(1, 4) for 1.2.1.1. and so on
-unstructured_document = BaseMetadataExtractor().add_metadata(document=unstructured_document,
-                                                             directory="./",
-                                                             filename="example.docx",
-                                                             converted_filename="example.doc",
-                                                             original_filename="example.docx")
+metadata = BaseMetadataExtractor().extract_metadata(directory="./", filename="example.docx", converted_filename="example.doc", original_filename="example.docx")
+unstructured_document.metadata = metadata
diff --git a/tests/unit_tests/test_doctype_law_txt_reader.py b/tests/unit_tests/test_doctype_law_txt_reader.py
index 391075b5..62d3e739 100644
--- a/tests/unit_tests/test_doctype_law_txt_reader.py
+++ b/tests/unit_tests/test_doctype_law_txt_reader.py
@@ -20,7 +20,7 @@ def test_law_document_spaces_correctness(self) -> None:
         path = self._get_abs_path("коап_москвы_8_7_2015_utf.txt")
         directory, filename = os.path.split(path)
         document = self.txt_reader.read(path=path, document_type="law", parameters={})
-        document = self.metadata_extractor.add_metadata(document, directory, filename, filename, filename)
+        document.metadata = self.metadata_extractor.extract_metadata(directory, filename, filename, filename)
         document = self.law_extractor.extract_structure(document, {})
 
         self.assertListEqual([], document.attachments)