super (copy.length / 2, copy.length / 2, 0, 0); this.backing_buffer = (copy != null ? nio_cast (copy) : null);
super (cap, lim, off, 0); this.backing_buffer = new char [cap];
  CharBufferImpl (byte[] copy)  {    super (copy.length / 2, copy.length / 2, 0, 0);    this.backing_buffer = (copy != null ? nio_cast (copy) : null);    readOnly = false;  }