[yk]

That's entirely implementation dependent. For existing libraries I would expect something like

    def get(self, query):
        if isinstance(query, template):
            self.get_template(query)
        else:
            self.get_old(query) #Don't break old code!

[ewidar]

it would likely be safer to have a safe (accepting Templates) and an unsafe (accepting strings) interface.

Now whether maintainers introduce `getSafe` and keep the old behavior intact, or make a breaking change to turn `get` into `getUnsafe`, we will see

[darthwalsh]

And they could add deprecation warnings gradually