[Glen] went to the park with his sister, [Emily], and his father, [Nicholas]. The three of them had a wonderful time there.
('Emily', 'Nicholas')
[Glen] went to the park with his sister, [Emily], and his father, [Nicholas]. The three of them had a wonderful time there.
[{('Emily', 'father', 'Nicholas'): [('Emily', 'brother', 'Glen'), ('Glen', 'father', 'Nicholas')]}]
['brother', 'father']