code: def register_model(self, identifier, properties, parameters, outputs):
          
          # Create object handle and store it in database before returning it
          obj = ModelHandle(identifier, properties, parameters, outputs)
          self.insert_object(obj)
          return obj
docs: Create an experiment object for the subject and image group. Objects
          are referenced by their identifier. The reference to a functional data
          object is optional.
  
          Raises ValueError if no valid experiment name is given in property list.
  
          Parameters
          ----------
          identifier : string
              Unique model identifier
          properties : Dictionary
              Dictionary of model specific properties.
          parameters : list(scodata.attribute.AttributeDefinition)
              List of attribute definitions for model run parameters
          outputs : ModelOutputs
              Description of model outputs
  
          Returns
          -------
          ModelHandle
              Handle for created model object in database