PHPUnit - Check if an array contains an object of that type

While unit testing in PHPUnit, I'm in a situation where I need to check if an array contains al least one object of a specific type.

Obviously I can do that with custom code, but is there any assertion (or combination of them) which allows me to do that?

I need to do that many times in multiple tests so, if the assertion I need doesn't esist, how do I extend the set of PHPUnit assertions?

Thank you