def debug(self):
return self.get('<STR_LIT>')<EOL>
Returns the set of debug facilities and which of them are
            currently enabled.

            Returns:
                dict

            >>> s = _syncthing().system
            >>> debug = s.debug()
            >>> debug
            ... #doctest: +ELLIPSIS
            {...}
            >>> len(debug.keys())
            2
            >>> 'enabled' in debug and 'facilities' in debug
            True
            >>> isinstance(debug['enabled'], list) or debug['enabled'] is None
            True
            >>> isinstance(debug['facilities'], dict)
            True