public function testXIntersectAcceptsCallback() { $xao = new XArray([1, 2, 'foo' => 'bar', 'x' => 'y', 4]); $test = new CallbackTestMethods(); $obj = $xao->xintersect(['xxx', 18], [$test, 'length_compare']); $this->assertEquals(['xxx'], (array) $obj); }