anchor.diff:    }
   }
   
  -// TODO(sra): Move to private library, like [NativeTypedArray].
   abstract class NativeTypedArrayOfDouble
       extends NativeTypedArray
           with ListMixin<double>, FixedLengthListMixin<double>
       implements List<double> {
  +
  +  num operator[](int index) {
  +    _checkIndex(index, length);
  +    return JS('num', '#[#]', this, index);
  +  }
  +
  +  void operator[]=(int index, num value) {
  +    _checkIndex(index, length);
  +    JS('void', '#[#] = #', this, index, value);
  +  }
   
     void setRange(int start, int end, Iterable<double> iterable,
                   [int skipCount = 0]) {
  
positive.code:    * `byteOffset + 8` is greater than the length of this object.
     */
    int getUint64(int byteOffset, [Endianness endian=Endianness.BIG_ENDIAN]) {
      throw new UnsupportedError("Uint64 accessor not supported by dart2js.");
    }
  
    /**
  
negative.code:   }
  }
  
  abstract class NativeTypedArrayOfInt
      extends NativeTypedArray
          with ListMixin<int>, FixedLengthListMixin<int>
      implements List<int> {
  
    // operator[]() is not here since different versions have different return
    // types
  
    void operator[]=(int index, int value) {
      _checkIndex(index, length);
      JS('void', '#[#] = #', this, index, value);
    }
  
    void setRange(int start, int end, Iterable<int> iterable,
                  [int skipCount = 0]) {
  