def release(self, conn):
self._in_use.remove(conn)<EOL>if conn.reader.at_eof() or conn.reader.exception():<EOL><INDENT>self._do_close(conn)<EOL><DEDENT>else:<EOL><INDENT>self._pool.put_nowait(conn)<EOL><DEDENT>
Releases connection back to the pool.

        :param conn: ``namedtuple`` (reader, writer)