[Heidi] offered to watch her father [Wayne]'s cats while he was on vacation with his father, [Clarence].
('Heidi', 'Clarence')
[Heidi] offered to watch her father [Wayne]'s cats while he was on vacation with his father, [Clarence].
[{('Heidi', 'grandfather', 'Clarence'): [('Heidi', 'father', 'Wayne'), ('Wayne', 'father', 'Clarence')]}]
['father', 'father']