In my experience this is almost never the case. #supports_feature? would be defined right there where you'd expect - in that Subscription model.

Even tough you can reach for metaprogramming (like define_method or method_missing), that's really not how the entire ecosystem of guides and tutorials will point you.

Anyways, when in doubt, just plug a debugger and call "@subscription.method(:supports_feature?).source_location`, and generally that's all it takes.