def free_identifier(self, lineno=None):
        """Return a new free identifier as :class:`~jinja2.nodes.InternalName`."""
        self._last_identifier += 1
        rv = object.__new__(nodes.InternalName)
        nodes.Node.__init__(rv, 'fi%d' % self._last_identifier, lineno=lineno)
        return rv
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/jinja2-2.6/jinja2/parser.py/Parser.free_identifier/original