code: def _conf_changed(self, arg):
          
  
          conf = parse_keywords(arg, multiline_values=False)
          for (k, v) in conf.items():
              # v will be txtorcon.DEFAULT_VALUE already from
              # parse_keywords if it was unspecified
              real_name = self._find_real_name(k)
              if real_name in self.parsers:
                  v = self.parsers[real_name].parse(v)
              self.config[real_name] = v
docs: internal callback. from control-spec:
  
          4.1.18. Configuration changed
  
            The syntax is:
               StartReplyLine *(MidReplyLine) EndReplyLine
  
               StartReplyLine = "650-CONF_CHANGED" CRLF
               MidReplyLine = "650-" KEYWORD ["=" VALUE] CRLF
               EndReplyLine = "650 OK"
  
            Tor configuration options have changed (such as via a SETCONF or
            RELOAD signal). KEYWORD and VALUE specify the configuration option
            that was changed.  Undefined configuration options contain only the
            KEYWORD.