public function testRandKeysAndValuesExist()
{
$xao = new XArray(['foo', 'bar']);
$obj = $xao->rand();
$keys = array_keys((array) $obj);
$this->assertArrayHasKey($keys[0], $obj);
$values = array_values((array) $obj);
$this->assertContains($values[0], $obj);
}