public function testCanSortKeys()
{
$under = Arr::sortKeys(['z' => 0, 'b' => 1, 'r' => 2]);
$this->assertEquals(['b' => 1, 'r' => 2, 'z' => 0], $under);
$under = Arr::sortKeys(['z' => 0, 'b' => 1, 'r' => 2], 'desc');
$this->assertEquals(['z' => 0, 'r' => 2, 'b' => 1], $under);
}
