'Update the mappings between infoset and keys.'

def update_infoset_map(self, infoset, keys, mainInfoset):

    if (keys is None):
        keys = []
    if (mainInfoset is not None):
        theIS = mainInfoset
    else:
        theIS = infoset
    self.infoset2keys[theIS] = keys
    for key in keys:
        self.key2infoset[key] = theIS
