MathPHP\SetTheory\SetOperationsTest::dataProviderForCartesianProduct PHP Метод

    public function dataProviderForCartesianProduct()
    {
        return [[[1, 2], [3, 4], ['Set{1, 3}' => new Set([1, 3]), 'Set{1, 4}' => new Set([1, 4]), 'Set{2, 3}' => new Set([2, 3]), 'Set{2, 4}' => new Set([2, 4])], new Set([new Set([1, 3]), new Set([1, 4]), new Set([2, 3]), new Set([2, 4])])], [[1, 2], ['red', 'white'], ['Set{1, red}' => new Set([1, 'red']), 'Set{1, white}' => new Set([1, 'white']), 'Set{2, red}' => new Set([2, 'red']), 'Set{2, white}' => new Set([2, 'white'])], new Set([new Set([1, 'red']), new Set([1, 'white']), new Set([2, 'red']), new Set([2, 'white'])])], [[1, 2], [], [], new Set()]];
    }