code: def extension(self, file_type: Optional[FileType] = None) -> str:
          
          key = self._validate_enum(item=file_type, enum=FileType)
          extensions = EXTENSIONS[key]
          return self.random.choice(extensions)
docs: Get a random file extension from list.
  
          :param file_type: Enum object FileType.
          :return: Extension of the file.
  
          :Example:
              .py