recorder.mutations << input
        }

        @Mutate
        void a(MutationRecorder recorder, @Path("firstInput") String input) {
            recorder.mutations << input
        }
    }

    static class FirstInputCreationRule extends RuleSource {
        @Model
        String firstInput() {
            "first"
        }
    }

    static class SecondInputCreationRule extends RuleSource {

            }

            class NestedBean {
                @Input
                String firstInput

                @InputFile
                File firstInputFile

                @OutputFile
                File firstOutputFile

                String toString() {
                    firstInput
                }

                void doStuff() {

                                PatternRewriter& rewriter) const override {
    TFL::PackOp pack_op = cast<TFL::PackOp>(op);
    Operation* first_input = pack_op.getOperand(0).getDefiningOp();
    if (!first_input) return failure();
    auto input_unpack_op = dyn_cast_or_null<TFL::UnpackOp>(first_input);
    if (!input_unpack_op) return failure();

    // The unpack & pack should have the same axis & num inputs/outputs.