def add_inputs(self, xs):
        """
        returns the list of states obtained by adding the given inputs
        to the current state, one by one.
        """
        states = []
        cur = self
        for x in xs:
            cur = cur.add_input(x)
            states.append(cur)
        return states
def add_inputs(self, xs):
        """
        returns the list of states obtained by adding the given inputs
        to the current state, one by one.
        """
        states = []
        cur = self
        for x in xs:
            cur = cur.add_input(x)
            states.append(cur)
        return states
returns the list of states obtained by adding the given inputs
        to the current state, one by one.