def reset(self, state_size_changed=False):
        """Reset parser state.

        Parameters
        ----------
        state_size_changed : `bool`, optional
            `True` if maximum state size changed (default: `False`).
        """
        if state_size_changed:
            self.state = deque(repeat('', self.state_size),
                               maxlen=self.state_size)
        else:
            self.state.extend(repeat('', self.state_size))
        self.end = True