code: def _make_entity_from_id(entity_cls, entity_obj_or_id, server_config):
      
      if isinstance(entity_obj_or_id, entity_cls):
          return entity_obj_or_id
      return entity_cls(server_config, id=entity_obj_or_id)
docs: Given an entity object or an ID, return an entity object.
  
      If the value passed in is an object that is a subclass of :class:`Entity`,
      return that value. Otherwise, create an object of the type that ``field``
      references, give that object an ID of ``field_value``, and return that
      object.
  
      :param entity_cls: An :class:`Entity` subclass.
      :param entity_obj_or_id: Either a :class:`nailgun.entity_mixins.Entity`
          object or an entity ID.
      :returns: An ``entity_cls`` object.
      :rtype: nailgun.entity_mixins.Entity