def METHOD_NAME(self):
    """Test that the path exists.
    Raises:
      CacheError: if the path does not exist.
    """
    if not os.path.exists(self.path):
        raise CacheError(f"Cache path does not exist: {self.path}")
    if not os.path.isdir(self.path):
        raise CacheError(f"Cache path is not a directory: {self.path}")