@acquire<EOL><INDENT>def set(self, conn, key, value, exptime=<NUM_LIT:0>):<DEDENT>
flags = <NUM_LIT:0>  <EOL>resp = yield from self._storage_command(<EOL>conn, b'<STR_LIT>', key, value, flags, exptime)<EOL>return resp<EOL>
Sets a key to a value on the server
        with an optional exptime (0 means don't auto-expire)

        :param key: ``bytes``, is the key of the item.
        :param value: ``bytes``, data to store.
        :param exptime: ``int``, is expiration time. If it's 0, the
        item never expires.
        :return: ``bool``, True in case of success.