def close_member(self):
        """Closes the current member being written.
        """
        # The new member is not yet started, no need to close
        if self._new_member:
            return
            
        self.fileobj.write(self.compress.flush())
        write32u(self.fileobj, self.crc)
        # self.size may exceed 2GB, or even 4GB
        write32u(self.fileobj, self.size & 0xffffffffL)
        self.size = 0
        self.compress = zlib.compressobj(9,
                                         zlib.DEFLATED,
                                         -zlib.MAX_WBITS,
                                         zlib.DEF_MEM_LEVEL,
                                         0)
        self._new_member = True
Closes the current member being written.