function = null;
    }

    /*
     * If set()/setValue() throws an Error, we let it propagate. Why? The most likely Error is a
     * StackOverflowError (from deep transform(..., directExecutor()) nesting), and calling
     * setException(stackOverflowError) would fail:
     *
     * - If the stack overflowed before set()/setValue() could even store the result in the output