docs: def serve_post(self, path, postmap, **params):
          """
          Find a POST callback for the given HTTP path, call it and return
          the results.  The callback is called with the path used to match
          it, a dict of vars from the POST body and params which include the
          BaseHTTPRequestHandler instance.
  
          The callback must return a tuple:
  
              (code, content, content_type)
  
          If multiple registrations match the path, the one with the longest
          matching text will be used.  Matches are always anchored at the start
          of the path.
  
          None is returned if no registered callback is willing to handle a path.
      """
          matched = self._match_path(path, self.post_registrations)
          if matched is None:                                                                     # pragma: no cover
              return None
          else:
              return matched(path, postmap, **params)