[Lillian] made chicken noodle soup for her son [Douglas]. [Douglas]'s brother [John] did n't want to have any.
('John', 'Lillian')
[Lillian] made chicken noodle soup for her son [Douglas]. [Douglas]'s brother [John] did n't want to have any.
[{('John', 'mother', 'Lillian'): [('John', 'brother', 'Douglas'), ('Douglas', 'mother', 'Lillian')]}]
['brother', 'mother']