Parkour\TraverseTest::testMapKeys PHP Method

    public function testMapKeys()
    {
        $data = ['a' => 1, 'b' => 2];
        $closure = $this->closure([[1, 'a', 'c'], [2, 'b', 'd']]);
        $expected = ['c' => 1, 'd' => 2];
        $this->assertEquals($expected, Traverse::mapKeys($data, $closure));
    }