anchor.diff:      JS('', '#[#] = #', array, i, value);
     }
   
  +  static JSArray arrayShallowCopy(Object array) =>
  +      JS('JSArray', '#.slice()', array);
  +
     static JSArray arraySplice(Object array, int position) =>
         JS('JSArray', '#.splice(#)', array, position);
   
  
positive.code: @pragma('dart2js:noInline')
  Rti instantiatedGenericFunctionType(
      Rti genericFunctionRti, Rti instantiationRti) {
    // TODO(fishythefish)
    throw UnimplementedError('instantiatedGenericFunctionType');
  }
  
  bool _isClosure(object) => _Utils.instanceOf(object,
  
negative.code:   /// between 'generic class is the base environment' and 'generic class is a
    /// singleton type argument' is resolved [TBD] (either (1) a bind1 cache, or
    /// (2)using `env._eval("@<0>")._bind(args)` in place of `env._bind1(args)`).
    ///
    /// On [Rti]s that are generic function types, results of instantiation are
    /// cached on the generic function type to ensure fast repeated
    /// instantiations.
    Object _bindCache;
  
    static Object _getBindCache(Rti rti) => rti._bindCache;
  