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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _validate_state_root(self, state_root):
 """Validates a state root, raising a ResponseFailed error if invalid. Args: state_root (str):
 The state_root to validate Raises: ResponseFailed: The state_root was invalid, and a status of INVALID_ROOT will be sent with the response. """

        if self._state_root_regex.fullmatch(state_root) is None:
            LOGGER.debug('Invalid state root: %s', state_root)
            raise _ResponseFailed(self._status.INVALID_ROOT)