public function collectionProvider() { $data = [1, 2, 3, 4]; $queue = new Queue(); $queue->push(1); $stack = new Stack(); $stack->push(1); return [[new Vector($data), '[1,2,3,4]'], [new Set($data), '[1,2,3,4]'], [new Map(['test' => 'test']), '{"test": "test"}'], [$queue, '[1]'], [$stack, '[1]']]; }