cleanup patch generation to preseve comments and remove @patch

test/generated_sdk/lib/collection/hash_map.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;
 
 /** Default function for equality comparison in customized HashMaps */
 bool _defaultEquals(a, b) => a == b;
 /** Default function for hash-code computation in customized HashMaps */
 int _defaultHashCode(a) => a.hashCode;
@@ skipping 15 matching lines @@
  * The map allows `null` as a key.
  *
  * Iterating the map's keys, values or entries (through [forEach])
  * may happen in any order.
  * The itearation order only changes when the map is modified.
  * Values are iterated in the same order as their associated keys,
  * so iterating the [keys] and [values] in parallel
  * will give matching key and value pairs.
  */
 abstract class HashMap<K, V> implements Map<K, V> {
-  @patch
+  /**
+   * Creates an unordered hash-table based [Map].
+   *
+   * The created map is not ordered in any way. When iterating the keys or
+   * values, the iteration order is unspecified except that it will stay the
+   * same as long as the map isn't changed.
+   *
+   * If [equals] is provided, it is used to compare the keys in the table with
+   * new keys. If [equals] is omitted, the key's own [Object.operator==] is used
+   * instead.
+   *
+   * Similar, if [hashCode] is provided, it is used to produce a hash value
+   * for keys in order to place them in the hash table. If it is omitted, the
+   * key's own [Object.hashCode] is used.
+   *
+   * If using methods like [operator[]], [remove] and [containsKey] together
+   * with a custom equality and hashcode, an extra `isValidKey` function
+   * can be supplied. This function is called before calling [equals] or
+   * [hashCode] with an argument that may not be a [K] instance, and if the
+   * call returns false, the key is assumed to not be in the set.
+   * The [isValidKey] function defaults to just testing if the object is a
+   * [K] instance.
+   *
+   * The used `equals` and `hashCode` method should always be consistent,
+   * so that if `equals(a, b)` then `hashCode(a) == hashCode(b)`. The hash
+   * of an object, or what it compares equal to, should not change while the
+   * object is in the table. If it does change, the result is unpredictable.
+   *
+   * If you supply one of [equals] and [hashCode],
+   * you should generally also to supply the other.
+   * An example would be using [identical] and [identityHashCode],
+   * which is equivalent to using the shorthand [HashMap.identity]).
+   */
   factory HashMap({ bool equals(K key1, K key2),
                     int hashCode(K key),
                     bool isValidKey(potentialKey) }) {
     if (isValidKey == null) {
       if (hashCode == null) {
         if (equals == null) {
           return new _HashMap<K, V>();
         }
         hashCode = _defaultHashCode;
       } else {
         if (identical(identityHashCode, hashCode) &&
             identical(identical, equals)) {
           return new _IdentityHashMap<K, V>();
         }
         if (equals == null) {
           equals = _defaultEquals;
         }
       }
     } else {
       if (hashCode == null) {
         hashCode = _defaultHashCode;
       }
       if (equals == null) {
         equals = _defaultEquals;
       }
     }
     return new _CustomHashMap<K, V>(equals, hashCode, isValidKey);
   }
 
-  @patch
+  /**
+   * Creates an unordered identity-based map.
+   *
+   * Effectively a shorthand for:
+   *
+   *     new HashMap(equals: identical, hashCode: identityHashCodeOf)
+   */
   factory HashMap.identity() = _IdentityHashMap<K, V>;
 
   /**
    * Creates a [HashMap] that contains all key/value pairs of [other].
    */
   factory HashMap.from(Map other) {
     HashMap<K, V> result = new HashMap<K, V>();
     other.forEach((k, v) { result[k] = v; });
     return result;
   }
@@ skipping 28 matching lines @@
    * overwrites the previous value.
    *
    * It is an error if the two [Iterable]s don't have the same length.
    */
   factory HashMap.fromIterables(Iterable<K> keys, Iterable<V> values) {
     HashMap<K, V> map = new HashMap<K, V>();
     Maps._fillMapWithIterables(map, keys, values);
     return map;
   }
 }