def args(self) -> Tuple:
        """Return the arguments for a trampolined function. If the function
        that is being trampolined has varargs, unroll the final argument if
        it is a sequence."""
        if not self._has_varargs:
            return self._args

        try:
            final = self._args[-1]
            if isinstance(final, ISeq):
                inits = self._args[:-1]
                return tuple(itertools.chain(inits, final))
            return self._args
        except IndexError:
            return ()