code: protected void removeDuplicates ()
      {
          if (_size > 1) {
              int last = _values[0];
              for (int ii = 1; ii < _size; ) {
                  if (_values[ii] == last) { // shift everything down 1
                      _size--;
                      System.arraycopy(_values, ii + 1, _values, ii, _size - ii);
                  } else {
                      last = _values[ii++];
                  }
              }
          }
      }
docs: Removes duplicates from our internal array. Only used by our constructors when initializing
  from a potentially duplicate-containing source array or collection.