def METHOD_NAME():
    tc.reset()
    c1 = Callable[[bool], bool]
    c2 = Callable[[bool], bool]
    unify_helper(c1, c2, c1)
    unify_helper(c1, c2, c2)
    unify_helper(c2, c1, c1)
    unify_helper(c2, c1, c2)