* collectsValues} is true, called for each future when all futures complete.
   */
  abstract void collectOneValue(int index, @ParametricNullness InputT returnValue);

  abstract void handleAllCompleted();

  /** Adds the chain to the seen set, and returns whether all the chain was new to us. */
  private static boolean addCausalChain(Set<Throwable> seen, Throwable param) {

      throws InvocationTargetException, IllegalAccessException {
    T returnValue = factory.invoke(null, args.toArray());
    if (returnValue == null) {
      Assert.assertTrue(
          factory + " returns null but it's not annotated with @Nullable", isNullable(factory));
    }
    return returnValue;
  }

  /**

    }

    void check() {
      runTester();
      FromTo<?, ?> defaultFunction = (FromTo<?, ?>) getDefaultParameterValue(0);
      FromTo<?, ?> returnValue = (FromTo<?, ?>) defaultFunction.apply(null);
      assertEquals("", returnValue.apply(null));
    }
  }

  public void testGenericInterfaceReturnedByGenericMethod() {
    new GenericInterface2DefaultValueChecker().check();
  }

  }

  private static <T> AsyncCallable<T> constantAsyncCallable(
      final @Nullable ListenableFuture<T> returnValue) {
    return new AsyncCallable<T>() {
      @Override
      public ListenableFuture<T> call() {
        return returnValue;
      }
    };
  }

  /** Runnable which can be called a single time, and only after {@link #expectCall} is called. */

  }

  private static <T> AsyncCallable<T> constantAsyncCallable(
      final @Nullable ListenableFuture<T> returnValue) {
    return new AsyncCallable<T>() {
      @Override
      public ListenableFuture<T> call() {
        return returnValue;
      }
    };
  }

  /** Runnable which can be called a single time, and only after {@link #expectCall} is called. */

    byte[] result = Files.readBytes(asciiFile, processor);
    assertEquals(Bytes.asList(Files.toByteArray(asciiFile)), Bytes.asList(result));
  }

  public void testReadBytes_returnFalse() throws IOException {
    ByteProcessor<byte[]> processor =
        new ByteProcessor<byte[]>() {
          private final ByteArrayOutputStream out = new ByteArrayOutputStream();

          @Override

    byte[] result = Files.readBytes(asciiFile, processor);
    assertEquals(Bytes.asList(Files.toByteArray(asciiFile)), Bytes.asList(result));
  }

  public void testReadBytes_returnFalse() throws IOException {
    ByteProcessor<byte[]> processor =
        new ByteProcessor<byte[]>() {
          private final ByteArrayOutputStream out = new ByteArrayOutputStream();

          @Override