code: def create_entity(self, name, gl_structure, description=None):
          
  
          new_entity = Entity(name, gl_structure, description=description)
          self.entities.append(new_entity)
          return new_entity
docs: Create an entity and add it to the model.
  
          :param name: The entity name.
          :param gl_structure: The entity's general ledger structure.
          :param description: The entity description.
  
          :returns: The created entity.