Don't use [operator==] to refer to [==] in DartDoc. It doesn't work.

sdk/lib/collection/hash_set.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.collection;
 
 /** Common parts of [HashSet] and [LinkedHashSet] implementations. */
 abstract class _HashSetBase<E> extends SetBase<E> {
 
   // The following two methods override the ones in SetBase.
@@ skipping 44 matching lines @@
    *
    * The provided [equals] must define a stable equivalence relation, and
    * [hashCode] must be consistent with [equals]. If the [equals] or [hashCode]
    * methods won't work on all objects, but only on some instances of E, the
    * [isValidKey] predicate can be used to restrict the keys that the functions
    * are applied to.
    * Any key for which [isValidKey] returns false is automatically assumed
    * to not be in the set when asking `contains`.
    *
    * If [equals] or [hashCode] are omitted, the set uses
-   * the elements' intrinsic [Object.operator==] and [Object.hashCode].
+   * the elements' intrinsic [Object.==] and [Object.hashCode].
    *
    * If you supply one of [equals] and [hashCode],
    * you should generally also to supply the other.
    *
    * If the supplied `equals` or `hashCode` functions won't work on all [E]
    * objects, and the map will be used in a setting where a non-`E` object
    * is passed to, e.g., `contains`, then the [isValidKey] function should
    * also be supplied.
    *
    * If [isValidKey] is omitted, it defaults to testing if the object is an
@@ skipping 53 matching lines @@
   }
 
   /**
    * Provides an iterator that iterates over the elements of this set.
    *
    * The order of iteration is unspecified,
    * but consistent between changes to the set.
    */
   Iterator<E> get iterator;
 }