code: def nullify(function):
      "Decorator. If empty list, returns None, else list."
      def wrapper(*args, **kwargs):
          value = function(*args, **kwargs)
          if(type(value) == list and len(value) == 0):
              return None
          return value
      return wrappef nullify(function):
      "Decorator. If empty list, returns None, else list."
      def wrapper(*args, **kwargs):
          value = function(*args, **kwargs)
          if(type(value) == list and len(value) == 0):
              return None
          return value
      return wrapper
docs: Decorator. If empty list, returns None, else list.