def __init__(self, prefix, routes):
        """Initializes a URL route.

        :param prefix:
            The prefix to be prepended. It must start with a slash but not
            end with a slash.
        :param routes:
            A list of :class:`webapp2.Route` instances.
        """
        assert prefix.startswith('/') and not prefix.endswith('/'), \
            'Path prefixes must start with a slash but not end with a slash.'
        super(PathPrefixRoute, self).__init__(prefix, routes)
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/webapp2-2.3/webapp2_extras/routes.py/PathPrefixRoute.__init__/original