transform(errorInput, newOneTimeErrorThrower(), directExecutor());
    errorInput.set(0);

    runGetIdempotencyTest(errorComposedFuture, MyError.class);

    /*
     * Try again when the input's value is already filled in, since the flow is
     * slightly different in that case.
     */
    exceptionComposedFuture =
        transform(exceptionInput, newOneTimeExceptionThrower(), directExecutor());

        transform(errorInput, newOneTimeErrorThrower(), directExecutor());
    errorInput.set(0);

    runGetIdempotencyTest(errorComposedFuture, MyError.class);

    /*
     * Try again when the input's value is already filled in, since the flow is
     * slightly different in that case.
     */
    exceptionComposedFuture =
        transform(exceptionInput, newOneTimeExceptionThrower(), directExecutor());

   * receiver can store the {@link ValueAndCloser} outside the receiver for later synchronous use.
   *
   * <p>After calling this method, you may not call {@link #finishToFuture()}, this method again, or
   * any other derivation method on the original {@code ClosingFuture} instance.
   *
   * @param consumer a callback whose method will be called (using {@code executor}) when this
   *     operation is done