[Douglas] and his brother [John] were rough-housing. [Lillian], [John]'s mother, called from the other room and told them to play nice.
('Douglas', 'Lillian')
[Douglas] and his brother [John] were rough-housing. [Lillian], [John]'s mother, called from the other room and told them to play nice.
[{('Douglas', 'mother', 'Lillian'): [('Douglas', 'brother', 'John'), ('John', 'mother', 'Lillian')]}]
['brother', 'mother']