| Index: sdk/lib/core/collection.dart | 
| diff --git a/sdk/lib/core/collection.dart b/sdk/lib/core/collection.dart | 
| index 703af88916480aba6752c109c3c41ebb9b9f1021..23b08e6b4b008e89eb954a2ff696923b0fdb1f34 100644 | 
| --- a/sdk/lib/core/collection.dart | 
| +++ b/sdk/lib/core/collection.dart | 
| @@ -11,91 +11,5 @@ part of dart.core; | 
| * an iterator based collection. | 
| */ | 
| abstract class Collection<E> extends Iterable<E> { | 
| -  /** | 
| -   * Returns a new collection with the elements [: f(e) :] | 
| -   * for each element [:e:] of this collection. | 
| -   * | 
| -   * Subclasses of [Collection] should implement the [map] method | 
| -   * to return a collection of the same general type as themselves. | 
| -   * E.g., [List.map] should return a [List]. | 
| -   */ | 
| -  Collection map(f(E element)); | 
| - | 
| -  /** | 
| -   * Returns a collection with the elements of this collection | 
| -   * that satisfy the predicate [f]. | 
| -   * | 
| -   * The returned collection should be of the same type as the collection | 
| -   * creating it. | 
| -   * | 
| -   * An element satisfies the predicate [f] if [:f(element):] | 
| -   * returns true. | 
| -   */ | 
| -  Collection<E> filter(bool f(E element)); | 
| - | 
| -  /** | 
| -   * Returns the number of elements in this collection. | 
| -   */ | 
| -  int get length; | 
| - | 
| -  /** | 
| -   * Check whether the collection contains an element equal to [element]. | 
| -   */ | 
| -  bool contains(E element) { | 
| -    for (E e in this) { | 
| -      if (e == element) return true; | 
| -    } | 
| -    return false; | 
| -  } | 
| - | 
| -  /** | 
| -   * Applies the function [f] to each element of this collection. | 
| -   */ | 
| -  void forEach(void f(E element)) { | 
| -    for (E element in this) f(element); | 
| -  } | 
| - | 
| -  /** | 
| -   * Reduce a collection to a single value by iteratively combining each element | 
| -   * of the collection with an existing value using the provided function. | 
| -   * Use [initialValue] as the initial value, and the function [combine] to | 
| -   * create a new value from the previous one and an element. | 
| -   * | 
| -   * Example of calculating the sum of a collection: | 
| -   * | 
| -   *   collection.reduce(0, (prev, element) => prev + element); | 
| -   */ | 
| -  dynamic reduce(var initialValue, | 
| -                 dynamic combine(var previousValue, E element)) { | 
| -    var value = initialValue; | 
| -    for (E element in this) value = combine(value, element); | 
| -    return value; | 
| -  } | 
| - | 
| -  /** | 
| -   * Returns true if every elements of this collection satisify the | 
| -   * predicate [f]. Returns false otherwise. | 
| -   */ | 
| -  bool every(bool f(E element)) { | 
| -    for (E element in this) { | 
| -      if (!f(element)) return false; | 
| -    } | 
| -    return true; | 
| -  } | 
| - | 
| -  /** | 
| -   * Returns true if one element of this collection satisfies the | 
| -   * predicate [f]. Returns false otherwise. | 
| -   */ | 
| -  bool some(bool f(E element)) { | 
| -    for (E element in this) { | 
| -      if (f(element)) return true; | 
| -    } | 
| -    return false; | 
| -  } | 
| - | 
| -  /** | 
| -   * Returns true if there is no element in this collection. | 
| -   */ | 
| -  bool get isEmpty => !iterator().hasNext; | 
| +  const Collection(); | 
| } | 
|  |