'null', 1 => 'first', 2 => 'second', ]; test('Single item', function () use ($arr) { Assert::same('null', Arrays::pick($arr, '')); Assert::same('first', Arrays::pick($arr, 1)); Assert::same('x', Arrays::pick($arr, 1, 'x')); Assert::exception( fn() => Arrays::pick($arr, 'undefined'), Nette\InvalidArgumentException::class, "Missing item 'undefined'.", ); Assert::same([2 => 'second'], $arr); });