docs: def create_entity(self, entity_type, term_ids, id=None):
          """
          Create a new (named) entity and add it to the entities layer
          @type entity_type: string
          @param entity_type: The type of the entity
          @type term_ids: list
          @param term_ids: list of term ids
          @type id: string
          @param id: optional id of the entity
          """
          new_entity = Centity(type=self.type)
          if id is None:
              n = 1 if self.entity_layer is None else len(self.entity_layer.map_entity_id_to_node) + 1
              id = "e{n}".format(**locals())
          new_entity.set_id(id)
          new_entity.set_type(entity_type)
          references = Creferences()
          references.add_span(term_ids)
          new_entity.add_reference(references)
          self.add_entity(new_entity)
          return new_entity