docs: def regex_filter(config, message, pattern=None, *args, **kw):
      """ All messages matching a regular expression
  
      Use this rule to include messages that bear a certain pattern.
      This can be anything that appears anywhere in the message (for instance,
      you could combine this with rules for wiki updates or Ask Fedora changes
      to alert yourself of activity in your area of expertise).
  
      (*i.e., (beefy miracle)*).
      """
  
      pattern = kw.get('pattern', pattern)
      if pattern:
          regex = fmn.rules.utils.compile_regex(pattern.encode('utf-8'))
          return bool(regex.search(
              fedmsg.encoding.dumps(message['msg']).encode('utf-8')
          ))