You said it was a dynamic typing issue, not a duck typing one, when in fact the two are inseparable in the example you gave. That is absolutely an example of du

You said it was a dynamic typing issue, not a duck typing one, when in fact the two are inseparable in the example you gave. That is absolutely an example of duck typing, you’re calling the same method on three different types with no subtyping relationship with a single invocation.