code: public IntBuffer compact () {
        byteBuffer.limit(limit << 2);
        byteBuffer.position(position << 2);
        byteBuffer.compact();
        byteBuffer.clear();
        position = limit - position;
        limit = capacity;
        mark = UNSET_MARK;
        return this;
      }
docs: Compacts this int buffer.
  <p> The remaining ints will be moved to the head of the buffer, starting from position zero.
  Then the position is set to {@code remaining()}; the limit is set to capacity; the mark is
  cleared. </p>
  
  @return this buffer.
  @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.