def METHOD_NAME(self):
    """
    Returns a dictionary mapping each node to its list of possible states.
    Returns
    -------
    state_dict: dict
        Dictionary of nodes to possible states
    """
    state_names_list = [phi.state_names for phi in self.factors]
    state_dict = {
        node: METHOD_NAME for d in state_names_list for node, METHOD_NAME in d.items()
    }
    return state_dict