code: def _to_deprecated_string(self):
          
          # pylint: disable=missing-format-attribute
          url = u"/{0.DEPRECATED_TAG}/{0.course_key.org}/{0.course_key.course}/{0.block_type}/{0.block_id}".format(self)
          if self.course_key.branch:
              url += u'@{}'.format(self.course_key.branch)
          return url
docs: Returns an old-style location, represented as:
  
          /c4x/org/course/category/name