def read_chunk(self, chunk):
_complain_ifclosed(self.closed)<EOL>return self.f.readinto(chunk)<EOL>
r"""
        Works like :meth:`read`\ , but data is stored in the writable
        buffer ``chunk`` rather than returned. Reads at most a number of
        bytes equal to the size of ``chunk``\ .

        :type chunk: buffer
        :param chunk: a writable object that supports the buffer protocol
        :rtype: int
        :return: the number of bytes read