def _tee(self, length):
        buf2 = self.buf
        buf2.seek(0, 2)
        chunk = self.stream.read(length)
        if chunk:
            self.tmp.write(chunk)
            self.tmp.flush()
            self.tmp.seek(0, 2)
            return chunk

        self._finalize()
        return ""
fetch partial body
dataset/ETHPy150Open benoitc/restkit/restkit/tee.py/TeeInput._tee