code: def RemoveClass(self, class_name):
      
      if class_name not in self._class_mapping:
        raise problems.NonexistentMapping(class_name)
      del self._class_mapping[class_name]
docs: Removes an entry from the list of known classes.
  
      Args:
          class_name: A string with the class name that is to be removed.
      Raises:
          NonexistentMapping if there is no class with the specified class_name.