code: def set_defaults(key):
      
  
      def decorator(func):
          @functools.wraps(func)
          def wrapper(phase, new_value):
              new_value = new_value or []
              for item in new_value:
                  # noinspection PyTypeChecker
                  galaxy = new_value[item] if isinstance(item, str) else item
                  galaxy.redshift = galaxy.redshift or conf.instance.general.get("redshift", key, float)
              return func(phase, new_value)
  
          return wrapper
  
      return decorator
docs: Load a default value for redshift from config and set it as the redshift for source or lens galaxies that have
      falsey redshifts
  
      Parameters
      ----------
      key: str
  
      Returns
      -------
      decorator
          A decorator that wraps the setter function to set defaults