[John] likes playing catch with his sister [April], but his brother [Jerry] never wants to play.
('April', 'Jerry')
[John] likes playing catch with his sister [April], but his brother [Jerry] never wants to play.
[{('April', 'brother', 'Jerry'): [('April', 'brother', 'John'), ('John', 'brother', 'Jerry')]}]
['brother', 'brother']