Appended a new state to this VFGNode.
        :param s: The new state to append
        :param is_widened_state: Whether it is a widened state or not.

def append_state(self, s, is_widened_state=False):
        """
        Appended a new state to this VFGNode.
        :param s: The new state to append
        :param is_widened_state: Whether it is a widened state or not.
        """

        if not is_widened_state:
            self.all_states.append(s)
            self.state = s

        else:
            self.widened_state = s