How to find whether a ring contains a matching item

Is there a built-in way to test whether a ring contains a particular item? Something like the array’s .contains? method (which does not work for rings)?
I suppose I could brute force roll my own, but I don’t want to reinvent the wheel.
Still hoping for a list of all methods for the VectorRing class – is there somewhere I could look at the ruby sourcecode for sonic pi?

Ok, I figured some stuff out.
First of all, you can ask any ruby object what its methods are. So:
puts SonicPi::Core::RingVector.instance_methods
gives a list of methods.
One method I found particularly valuable is “vec”, which turns a ring into a standard ruby array, which you can then search easily.
So I can find an element in a ring like so:

myring = (ring 1, 2, 3, 4, 5, 6)
puts myring.vec.include? 3
puts myring.vec.include? 7

I’ll list all methods in the thread discussing ring methods.