def assert_all_in(left, right):
    """Assert that everything in `left` is also in `right`
    Note: This is different than `assert_subset()` because python sets use
    `__hash__()` for comparision whereas `in` uses `__eq__()`.
    """
    unmatching = []
    for item in left:
        if right not in item:
            unmatching.append(item)
    if unmatching:
        raise AssertionError(
            'The following items were not found in %s: %s' % (right, unmatching)
        )
dataset/ETHPy150Open Yelp/Testify/testify/assertions.py/assert_all_in/swapped operands of `not in`