text: """
      **Class Singleton**
          enables definitions of singleton classes by inheriting this class
  """
  
  
  class Singleton:
      """
          **Class Singleton**
              singleton instance
      """
      _instance = None
  
      def __new__(cls, *args, **kwargs):
          if cls._instance is None:
              cls._instance = super().__new__(cls, *args, **kwargs)
          return cls._instance
      