def _cache_ops_associate(protocol, msgtype):
ops = cache_ops<EOL>while ops:  <EOL><INDENT>if ops.co_protocol == protocol:<EOL><INDENT>for co_msgtype in ops.co_msgtypes:<EOL><INDENT>if co_msgtype.mt_id == msgtype:<EOL><INDENT>return ops<EOL><DEDENT><DEDENT><DEDENT>ops = ops.co_next<EOL><DEDENT>return None<EOL>
https://github.com/thom311/libnl/blob/libnl3_2_25/lib/cache_mngt.c#L111.

    Positional arguments:
    protocol -- Netlink protocol (integer).
    msgtype -- Netlink message type (integer).

    Returns:
    nl_cache_ops instance with matching protocol containing matching msgtype or None.