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

sdk/lib/async/zone.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.async;
 
 typedef R ZoneCallback<R>();
 typedef R ZoneUnaryCallback<R, T>(T arg);
 typedef R ZoneBinaryCallback<R, T1, T2>(T1 arg1, T2 arg2);
 
@@ skipping 381 matching lines @@
    */
   bool inSameErrorZone(Zone otherZone);
 
   /**
    * Creates a new zone as a child of `this`.
    *
    * The new zone uses the closures in the given [specification] to override
    * the current's zone behavior. All specification entries that are `null`
    * inherit the behavior from the parent zone (`this`).
    *
-   * The new zone inherits the stored values (accessed through [operator []])
+   * The new zone inherits the stored values (accessed through [[]])
    * of this zone and updates them with values from [zoneValues], which either
    * adds new values or overrides existing ones.
    *
    * Note that the fork operation is interceptible. A zone can thus change
    * the zone specification (or zone values), giving the forking zone full
    * control over the child zone.
    */
   Zone fork({ZoneSpecification specification,
              Map zoneValues});
 
@@ skipping 1083 matching lines @@
                                    handleUncaughtError: errorHandler);
   }
   Zone zone = Zone.current.fork(specification: zoneSpecification,
                                 zoneValues: zoneValues);
   if (onError != null) {
     return zone.runGuarded(body);
   } else {
     return zone.run(body);
   }
 }