def _is_tuple_of_dyads(states):
    """Check if the object is a tuple or list of dyads
    
    """
    
    def _is_a_dyad(dd):
        return len(dd) == 2
    
    ret = False
    for st in states:
        if _is_a_dyad(st):
            ret = True
        else:
            ret = False
            break
        
    return ret