code: def get_relationship(cls, request_args, id, related_collection_name, related_resource=None):
          
          try:
              included = request_args.get('include').split(',')
          except (SyntaxError, AttributeError):
              included = []
          try:
              offset = request_args.get('page[offset]', 0)
              limit = request_args.get('page[limit]', 20)
              this_resource = cls.nodes.get(id=id, active=True)
              if not related_resource:
                  if request_args.get('include'):
                      r = application_codes.error_response([application_codes.PARAMETER_NOT_SUPPORTED_VIOLATION])
                  else:
                      r = this_resource.relationship_collection_response(related_collection_name, offset, limit)
              else:  # deprecated for version 1.1.0
                  r = this_resource.individual_relationship_response(related_collection_name, related_resource, included)
  
          except DoesNotExist:
              r = application_codes.error_response([application_codes.RESOURCE_NOT_FOUND])
          return r
docs: Get a relationship
          :param request_args:
          :param id: The 'id' field of the node on the left side of the relationship in the database.  The id field must \
          be set in the model -- it is not the same as the node id
          :param related_collection_name: The name of the relationship
          :param related_resource: Deprecated for version 1.1.0
          :return: A response according to the specification at http://jsonapi.org/format/#fetching-relationships