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pkg/dev_compiler/tool/input_sdk/lib/core/object.dart

-// Copyright (c) 2012, 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.core;
-
-/**
- * The base class for all Dart objects.
- *
- * Because Object is the root of the Dart class hierarchy,
- * every other Dart class is a subclass of Object.
- *
- * When you define a class, you should override [toString]
- * to return a string describing an instance of that class.
- * You might also need to define [hashCode] and [==], as described in the
- * [Implementing map
- * keys](https://www.dartlang.org/docs/dart-up-and-running/ch03.html#implementing-map-keys)
- * section of the [library
- * tour](http://www.dartlang.org/docs/dart-up-and-running/contents/ch03.html).
- */
-class Object {
-  /**
-   * Creates a new [Object] instance.
-   *
-   * [Object] instances have no meaningful state, and are only useful
-   * through their identity. An [Object] instance is equal to itself
-   * only.
-   */
-  const Object();
-
-  /**
-   * The equality operator.
-   *
-   * The default behavior for all [Object]s is to return true if and
-   * only if [:this:] and [other] are the same object.
-   *
-   * Override this method to specify a different equality relation on
-   * a class. The overriding method must still be an equivalence relation.
-   * That is, it must be:
-   *
-   *  * Total: It must return a boolean for all arguments. It should never throw
-   *    or return `null`.
-   *
-   *  * Reflexive: For all objects `o`, `o == o` must be true.
-   *
-   *  * Symmetric: For all objects `o1` and `o2`, `o1 == o2` and `o2 == o1` must
-   *    either both be true, or both be false.
-   *
-   *  * Transitive: For all objects `o1`, `o2`, and `o3`, if `o1 == o2` and
-   *    `o2 == o3` are true, then `o1 == o3` must be true.
-   *
-   * The method should also be consistent over time, so equality of two objects
-   * should not change over time, or at least only change if one of the objects
-   * was modified.
-   *
-   * If a subclass overrides the equality operator it should override
-   * the [hashCode] method as well to maintain consistency.
-   */
-  bool operator ==(other) => identical(this, other);
-
-  /**
-   * Get a hash code for this object.
-   *
-   * All objects have hash codes. Hash codes are guaranteed to be the
-   * same for objects that are equal when compared using the equality
-   * operator [:==:]. Other than that there are no guarantees about
-   * the hash codes. They will not be consistent between runs and
-   * there are no distribution guarantees.
-   *
-   * If a subclass overrides [hashCode] it should override the
-   * equality operator as well to maintain consistency.
-   */
-  external int get hashCode;
-
-  /**
-   * Returns a string representation of this object.
-   */
-  external String toString();
-
-  /**
-   * Invoked when a non-existent method or property is accessed.
-   *
-   * Classes can override [noSuchMethod] to provide custom behavior.
-   *
-   * If a value is returned, it becomes the result of the original invocation.
-   *
-   * The default behavior is to throw a [NoSuchMethodError].
-   */
-  external dynamic noSuchMethod(Invocation invocation);
-
-  /**
-   * A representation of the runtime type of the object.
-   */
-  external Type get runtimeType;
-}