def __init__(self, message, parent=None):
super(ValidationError, self).__init__(message)<EOL>self.message = message<EOL>self._parents = []<EOL>if parent:<EOL><INDENT>self._parents.append(parent)<EOL><DEDENT>
Args:
    message (str): Error message detailing validation failure.
    parent (str): Adds the parent as the closest reference point for
        the error. Use :meth:`add_parent` to add more.