code: public void write(String s, int offset, int length)
      throws IOException
    {
      while (length > 0) {
        if (_tail == null)
          addBuffer(TempCharBuffer.allocate());
        else if (_tail._buf.length <= _tail._length) {
          addBuffer(TempCharBuffer.allocate());
  
          // XXX: see TempStream for backing files
        }
  
        int sublen = _tail._buf.length - _tail._length;
        if (length < sublen)
          sublen = length;
  
        s.getChars(offset, offset + sublen, _tail._buf, _tail._length);
  
        offset += sublen;
        length -= sublen;
        _tail._length += sublen;
      }
    }
docs: Writes part of a string.