diff --git a/package.json b/package.json
index 518dc73..7ea72d9 100644
--- a/package.json
+++ b/package.json
@@ -36,6 +36,7 @@
     "@babel/node": "7.8.7",
     "@babel/plugin-proposal-class-properties": "7.8.3",
     "@babel/plugin-proposal-object-rest-spread": "7.9.0",
+    "@babel/plugin-proposal-optional-chaining": "^7.11.0",
     "@babel/plugin-transform-flow-strip-types": "7.9.0",
     "@babel/plugin-transform-runtime": "7.9.0",
     "@babel/preset-env": "7.9.0",
diff --git a/yarn.lock b/yarn.lock
index 8b51ef3..9c90666 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -231,6 +231,11 @@
   resolved "https://registry.yarnpkg.com/@babel/helper-plugin-utils/-/helper-plugin-utils-7.8.3.tgz#9ea293be19babc0f52ff8ca88b34c3611b208670"
   integrity sha512-j+fq49Xds2smCUNYmEHF9kGNkhbet6yVIBp4e6oeQpH1RUs/Ir06xUKzDjDkGcaaokPiTNs2JBWHjaE4csUkZQ==
 
+"@babel/helper-plugin-utils@^7.10.4":
+  version "7.10.4"
+  resolved "https://registry.yarnpkg.com/@babel/helper-plugin-utils/-/helper-plugin-utils-7.10.4.tgz#2f75a831269d4f677de49986dff59927533cf375"
+  integrity sha512-O4KCvQA6lLiMU9l2eawBPMf1xPP8xPfB3iEQw150hOVTqj/rfXz0ThTb4HEzqQfs2Bmo5Ay8BzxfzVtBrr9dVg==
+
 "@babel/helper-regex@^7.8.3":
   version "7.8.3"
   resolved "https://registry.yarnpkg.com/@babel/helper-regex/-/helper-regex-7.8.3.tgz#139772607d51b93f23effe72105b319d2a4c6965"
@@ -277,6 +282,13 @@
     "@babel/template" "^7.8.3"
     "@babel/types" "^7.8.3"
 
+"@babel/helper-skip-transparent-expression-wrappers@^7.11.0":
+  version "7.11.0"
+  resolved "https://registry.yarnpkg.com/@babel/helper-skip-transparent-expression-wrappers/-/helper-skip-transparent-expression-wrappers-7.11.0.tgz#eec162f112c2f58d3af0af125e3bb57665146729"
+  integrity sha512-0XIdiQln4Elglgjbwo9wuJpL/K7AGCY26kmEt0+pRP0TAj4jjyNq1MjoRvikrTVqKcx4Gysxt4cXvVFXP/JO2Q==
+  dependencies:
+    "@babel/types" "^7.11.0"
+
 "@babel/helper-split-export-declaration@^7.8.3":
   version "7.8.3"
   resolved "https://registry.yarnpkg.com/@babel/helper-split-export-declaration/-/helper-split-export-declaration-7.8.3.tgz#31a9f30070f91368a7182cf05f831781065fc7a9"
@@ -284,6 +296,11 @@
   dependencies:
     "@babel/types" "^7.8.3"
 
+"@babel/helper-validator-identifier@^7.10.4":
+  version "7.10.4"
+  resolved "https://registry.yarnpkg.com/@babel/helper-validator-identifier/-/helper-validator-identifier-7.10.4.tgz#a78c7a7251e01f616512d31b10adcf52ada5e0d2"
+  integrity sha512-3U9y+43hz7ZM+rzG24Qe2mufW5KhvFg/NhnNph+i9mgCtdTCtMJuI1TMkrIUiK7Ix4PYlRF9I5dhqaLYA/ADXw==
+
 "@babel/helper-validator-identifier@^7.9.0":
   version "7.9.0"
   resolved "https://registry.yarnpkg.com/@babel/helper-validator-identifier/-/helper-validator-identifier-7.9.0.tgz#ad53562a7fc29b3b9a91bbf7d10397fd146346ed"
@@ -415,6 +432,15 @@
     "@babel/helper-plugin-utils" "^7.8.3"
     "@babel/plugin-syntax-optional-catch-binding" "^7.8.0"
 
+"@babel/plugin-proposal-optional-chaining@^7.11.0":
+  version "7.11.0"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-optional-chaining/-/plugin-proposal-optional-chaining-7.11.0.tgz#de5866d0646f6afdaab8a566382fe3a221755076"
+  integrity sha512-v9fZIu3Y8562RRwhm1BbMRxtqZNFmFA2EG+pT2diuU8PT3H6T/KXoZ54KgYisfOFZHV6PfvAiBIZ9Rcz+/JCxA==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.10.4"
+    "@babel/helper-skip-transparent-expression-wrappers" "^7.11.0"
+    "@babel/plugin-syntax-optional-chaining" "^7.8.0"
+
 "@babel/plugin-proposal-optional-chaining@^7.9.0":
   version "7.9.0"
   resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-optional-chaining/-/plugin-proposal-optional-chaining-7.9.0.tgz#31db16b154c39d6b8a645292472b98394c292a58"
@@ -945,6 +971,15 @@
     lodash "^4.17.13"
     to-fast-properties "^2.0.0"
 
+"@babel/types@^7.11.0":
+  version "7.11.5"
+  resolved "https://registry.yarnpkg.com/@babel/types/-/types-7.11.5.tgz#d9de577d01252d77c6800cee039ee64faf75662d"
+  integrity sha512-bvM7Qz6eKnJVFIn+1LPtjlBFPVN5jNDc1XmN15vWe7Q3DPBufWWsLiIvUu7xW87uTG6QoggpIDnUgLQvPheU+Q==
+  dependencies:
+    "@babel/helper-validator-identifier" "^7.10.4"
+    lodash "^4.17.19"
+    to-fast-properties "^2.0.0"
+
 "@babel/types@^7.4.4", "@babel/types@^7.7.0", "@babel/types@^7.8.6", "@babel/types@^7.9.0":
   version "7.9.0"
   resolved "https://registry.yarnpkg.com/@babel/types/-/types-7.9.0.tgz#00b064c3df83ad32b2dbf5ff07312b15c7f1efb5"
@@ -5588,6 +5623,11 @@ lodash@^4.17.10, lodash@^4.17.13, lodash@^4.17.14, lodash@^4.17.15, lodash@^4.17
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.15.tgz#b447f6670a0455bbfeedd11392eff330ea097548"
   integrity sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==
 
+lodash@^4.17.19:
+  version "4.17.20"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.20.tgz#b44a9b6297bcb698f1c51a3545a2b3b368d59c52"
+  integrity sha512-PlhdFcillOINfeV7Ni6oF1TAEayyZBoZ8bcshTHqOYJYlrqzRK5hagpagky5o4HfCzzd1TRkXPMFq6cKk9rGmA==
+
 lolex@^5.0.0:
   version "5.1.2"
   resolved "https://registry.yarnpkg.com/lolex/-/lolex-5.1.2.tgz#953694d098ce7c07bc5ed6d0e42bc6c0c6d5a367"