def get_source(self, environment, template):
        try:
            prefix, name = template.split(self.delimiter, 1)
            loader = self.mapping[prefix]
        except (ValueError, __HOLE__):
            raise TemplateNotFound(template)
        try:
            return loader.get_source(environment, name)
        except TemplateNotFound:
            # re-raise the exception with the correct fileame here.
            # (the one that includes the prefix)
            raise TemplateNotFound(template)
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/jinja2-2.6/jinja2/loaders.py/PrefixLoader.get_source