PHP trait: is there a proper way to ensure that class using a trait extends a super class which contains certain method?

No, there is not. In fact, this example is very bad, since the purpose of introducing traits was to introduce same functionality to many classes without relying on inheritance, and using parent not only requires class to have parent, but also it should have specific method.

While trying to figure this out on my own I'm currently stuck with code similar to this.

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