Rebase on latest package:collection

test/codegen/expect/collection/src/canonicalized_map.js

Index: test/codegen/expect/collection/src/canonicalized_map.js
diff --git a/test/codegen/expect/collection/src/canonicalized_map.js b/test/codegen/expect/collection/src/canonicalized_map.js
index ad42dd3c4b32dc65fe68fe881070a1f7314692dc..03744bc169ca52cb1f9dae9898e42e2c3e091135 100644
--- a/test/codegen/expect/collection/src/canonicalized_map.js
+++ b/test/codegen/expect/collection/src/canonicalized_map.js
@@ -32,9 +32,12 @@ dart_library.library('collection/src/canonicalized_map', null, /* Imports */[
         return pair == null ? null : pair.last;
       }
       set(key, value) {
-        dart.as(key, K);
-        dart.as(value, V);
-        this[_base].set(dart.as(dart.dcall(this[_canonicalize], key), C), new (utils.Pair$(K, V))(key, value));
+        (() => {
+          dart.as(key, K);
+          dart.as(value, V);
+          if (!dart.notNull(this[_isValidKey](key))) return;
+          this[_base].set(dart.as(dart.dcall(this[_canonicalize], key), C), new (utils.Pair$(K, V))(key, value));
+        })();
         return value;
       }
       addAll(other) {