text: import abc
  from typing import Any
  
  
  class Storage(object):
      __metaclass__ = abc.ABCMeta
  
      @abc.abstractmethod
      def read_data(self) -> Any:
          raise NotImplementedError
  
      @abc.abstractmethod
      def write_data(self, data: Any) -> None:
          raise NotImplementedError
  
      @abc.abstractmethod
      def append_data(self, data: Any) -> None:
          raise NotImplementedError
  
      @abc.abstractmethod
      def clean_data(self) -> None:
          raise NotImplementedError
  