def get_source(self, environment, template):
        if template in self.mapping:
            source = self.mapping[template]
            return source, None, lambda: source != self.mapping.get(template)
        raise TemplateNotFound(template)
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/jinja2-2.6/jinja2/loaders.py/DictLoader.get_source/original