code: @Override
    public void write(byte []buf, int offset, int length, boolean isEnd)
      throws IOException
    {
      if (buf == null)
        throw new NullPointerException();
      else if (offset < 0 || buf.length < offset + length)
        throw new ArrayIndexOutOfBoundsException();
  
      nativeWrite(_fd, buf, offset, length);
    }
docs: Writes data to the file.