def assert_installed(self, mods: Union[Any, Iterable[Any]]):
        """Check that the given modules `mods` are not dummies. If any is, show the
        optional requirement message.

        Returns self for chaining convenience.
        """
        if not isinstance(mods, Iterable):
            mods = [mods]

        if any(isinstance(mod, Dummy) for mod in mods):
            raise ModuleNotFoundError(self.messages.module_not_found)

        return self
Check that the given modules `mods` are not dummies. If any is, show the
        optional requirement message.

        Returns self for chaining convenience.
        
src/core/trulens/core/utils/imports.py