diff --git a/examples/attributes.rs b/examples/attributes.rs
index 51a8ab5..766b0f0 100644
--- a/examples/attributes.rs
+++ b/examples/attributes.rs
@@ -14,9 +14,12 @@ struct MyAttribute {
 fn main() {
     let mut dt = startin::Triangulation::new();
     dt.set_duplicates_handling(startin::DuplicateHandling::Highest);
-    let _ = dt.add_attribute_map("intensity".to_string(), "f64".to_string());
-    let _ = dt.add_attribute_map("classification".to_string(), "u64".to_string());
-    let _ = dt.add_attribute_map("visited".to_string(), "bool".to_string());
+    let att_schema: Vec<(String, String)> = vec![
+        ("intensity".to_string(), "f64".to_string()),
+        ("classification".to_string(), "u64".to_string()),
+        ("visited".to_string(), "bool".to_string()),
+    ];
+    let _ = dt.set_attributes_schema(att_schema);
 
     let a = MyAttribute {
         intensity: 44.0,
@@ -36,7 +39,7 @@ fn main() {
     let _ = dt.add_vertex_attributes(vi.unwrap(), json!({"classification": 1, "visited": true}));
 
     println!("{}", dt);
-    println!("{:?}\n", dt.list_all_attributes());
+    println!("{:?}\n", dt.all_attributes());
     println!("{:?}", dt.all_attributes());
 
     println!("{:?}", dt.get_vertex_attributes(4));
diff --git a/examples/example2.rs b/examples/example2.rs
index 0144a95..854b024 100644
--- a/examples/example2.rs
+++ b/examples/example2.rs
@@ -28,7 +28,7 @@ fn main() {
     let re = dt.insert_one_pt(22.2, 33.3, 4.4);
     match re {
         Ok(_v) => println!("Inserted new point"),
-        Err(v) => println!("Duplicate of vertex #{}, not inserted", v),
+        Err((v, _b)) => println!("Duplicate of vertex #{}, not inserted", v),
     }
     //-- remove it
     let re = dt.remove(6);
diff --git a/examples/readme_snippet.rs b/examples/readme_snippet.rs
index 580e96d..6210a86 100644
--- a/examples/readme_snippet.rs
+++ b/examples/readme_snippet.rs
@@ -24,7 +24,7 @@ fn main() {
             "Inserted new point, now the DT has {} vertices",
             dt.number_of_vertices()
         ),
-        Err(v) => println!("Duplicate of vertex #{}, not inserted", v),
+        Err((v, _b)) => println!("Duplicate of vertex #{}, not inserted", v),
     }
     //-- remove it
     match dt.remove(6) {
diff --git a/src/lib.rs b/src/lib.rs
index 619704b..669e285 100755
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -67,7 +67,7 @@
 //!             "Inserted new point, now the DT has {} vertices",
 //!             dt.number_of_vertices()
 //!         ),
-//!         Err(v) => println!("Duplicate of vertex #{}, not inserted", v),
+//!         Err((v, _b)) => println!("Duplicate of vertex #{}, not inserted", v),
 //!     }
 //!     //-- remove it
 //!     match dt.remove(6) {
@@ -540,8 +540,9 @@ impl Triangulation {
 
     /// Insert the point (`px`, `py`, `pz`) in the triangulation.
     /// Returns the vertex ID of the point if the vertex didn't exist.
-    /// If there was a vertex at that location, an Error is thrown with the already
-    /// existing vertex ID.
+    /// If there was a vertex at that location, an Error is thrown with a tuple
+    /// indicating 1) the vertex ID of the existing vertex; 2) true/false whether the
+    /// z-value and attributes were updated.
     pub fn insert_one_pt(&mut self, px: f64, py: f64, pz: f64) -> Result<usize, (usize, bool)> {
         if !self.is_init {
             return self.insert_one_pt_init_phase(px, py, pz);
diff --git a/tests/duplicates.rs b/tests/duplicates.rs
index 0725626..51e64f5 100755
--- a/tests/duplicates.rs
+++ b/tests/duplicates.rs
@@ -20,33 +20,33 @@ fn duplicate_alltests() {
 
     dt.set_duplicates_handling(startin::DuplicateHandling::First);
     let re = dt.insert_one_pt(5.0, 5.0, 20.0);
-    assert_eq!(Err(5), re);
+    assert_eq!(Err((5, false)), re);
     match re {
         Ok(_) => (),
-        Err(i) => assert_eq!(dt.get_point(i).unwrap()[2], 10.0),
+        Err((i, _b)) => assert_eq!(dt.get_point(i).unwrap()[2], 10.0),
     }
 
     dt.set_duplicates_handling(startin::DuplicateHandling::Last);
     let re = dt.insert_one_pt(5.0, 5.0, 20.0);
-    assert_eq!(Err(5), re);
+    assert_eq!(Err((5, true)), re);
     match re {
         Ok(_) => (),
-        Err(i) => assert_eq!(dt.get_point(i).unwrap()[2], 20.0),
+        Err((i, _b)) => assert_eq!(dt.get_point(i).unwrap()[2], 20.0),
     }
 
     dt.set_duplicates_handling(startin::DuplicateHandling::Highest);
-    let re = dt.insert_one_pt(5.0, 5.0, 20.0);
-    assert_eq!(Err(5), re);
+    let re = dt.insert_one_pt(5.0, 5.0, 21.0);
+    assert_eq!(Err((5, true)), re);
     match re {
         Ok(_) => (),
-        Err(i) => assert_eq!(dt.get_point(i).unwrap()[2], 20.0),
+        Err((i, _b)) => assert_eq!(dt.get_point(i).unwrap()[2], 21.0),
     }
 
     dt.set_duplicates_handling(startin::DuplicateHandling::Lowest);
     let re = dt.insert_one_pt(5.0, 5.0, 5.0);
-    assert_eq!(Err(5), re);
+    assert_eq!(Err((5, true)), re);
     match re {
         Ok(_) => (),
-        Err(i) => assert_eq!(dt.get_point(i).unwrap()[2], 5.0),
+        Err((i, _b)) => assert_eq!(dt.get_point(i).unwrap()[2], 5.0),
     }
 }
diff --git a/tests/init_construction.rs b/tests/init_construction.rs
index f1983c8..7aa22a0 100755
--- a/tests/init_construction.rs
+++ b/tests/init_construction.rs
@@ -43,7 +43,7 @@ fn duplicates() {
     let _re = dt.insert_one_pt(2.2, 2.3, 4.5);
     let re2 = dt.insert_one_pt(2.2, 2.3, 4.5);
     assert!(re2.is_err());
-    assert_eq!(2, re2.unwrap_err());
+    assert_eq!((2, false), re2.unwrap_err());
     assert_eq!(2, dt.number_of_vertices());
     assert_eq!(0, dt.number_of_triangles());
 }