Pinq\Tests\Integration\Traversable\GroupJoinTest::testGroupJoinProducesCorrectResult PHP Method

    public function testGroupJoinProducesCorrectResult(\Pinq\ITraversable $traversable, array $data)
    {
        $traversable = $traversable->groupJoin([1, 2, 2, 3, '4', '5'])->on(function ($outer, $inner) {
            return $outer === $inner;
        })->to(function ($outer, \Pinq\ITraversable $values) {
            return $outer . '-' . $values->implode('-');
        });
        $this->assertMatchesValues($traversable, ['1-1', '2-2-2', '3-3', '4-', '5-', '6-', '7-', '8-', '9-', '10-']);
    }