Py.BoolSourceInterface for Python values of type Bool.
The Python value True. This value is guaranteed to be the unique value associated to True.
Py.is_true v is true if and only if v is True. Since Py.Bool.t is guaranteed to be the unique value associated to True, Py.is_true v is equivalent to v == Py.t.
The Python value False. This value is guaranteed to be the unique value associated to False.
Py.is_false v is true if and only if v is False. Since Py.Bool.f is guaranteed to be the unique value associated to False, Py.is_false f is equivalent to v == Py.f.