code: def obsolete_client(func):
      
  
      @functools.wraps(func)
      def new_func(*args, **kwargs):
          raise ObsoleteException(
              "{} has been removed from this version of the library. "
              "Please refer to current documentation for guidance."
              .format(func.__name__)
          )
  
      return new_func
docs: This is a decorator which can be used to mark Client classes as
      obsolete. It will result in an error being emitted when the class is
      instantiated.