<compilerArgs combine.children="append">
                <!-- https://errorprone.info/docs/installation#maven -->
                <!-- TODO(cpovirk): Enable NullArgumentForNonNullParameter for
                     prod code. It's disabled automatically for "test code"
                     (which is good: our tests have intentional violations), but
                     Error Prone doesn't know it's building test code unless we

           * -4294967296L = -9223372036854775808L!
           *
           * To be clear, this bug affects not the test's computation of the expected result but the
           * _actual prod code_. But it probably affects only unusual cases.
           */
          continue;
        }
        BigInteger expectedResult = valueOf(a).multiply(valueOf(b));

  private void setPredecessor(int entry, int pred) {
    long predMask = ~0L << 32;
    setLink(entry, (link(entry) & ~predMask) | ((long) (pred + 1) << 32));
  }

  private void setSucceeds(int pred, int succ) {
    if (pred == ENDPOINT) {
      firstEntry = succ;
    } else {
      setSuccessor(pred, succ);
    }

    if (succ == ENDPOINT) {
      lastEntry = pred;
    } else {

  }

  private void setPredecessor(int entry, int pred) {
    requirePredecessors()[entry] = pred + 1;
  }

  private void setSucceeds(int pred, int succ) {
    if (pred == ENDPOINT) {
      firstEntry = succ;
    } else {
      setSuccessor(pred, succ);
    }

    if (succ == ENDPOINT) {
      lastEntry = pred;
    } else {
      setPredecessor(succ, pred);
    }
  }

  @Override

    /** Constructor for the header node. */
    AvlNode() {
      this.elem = null;
      this.elemCount = 1;
    }

    // For discussion of pred() and succ(), see the comment on the pred and succ fields.

    private AvlNode<E> pred() {
      return requireNonNull(pred);
    }

    private AvlNode<E> succ() {
      return requireNonNull(succ);
    }

      ValueSetLink<K, V> pred, ValueSetLink<K, V> succ) {
    pred.setSuccessorInValueSet(succ);
    succ.setPredecessorInValueSet(pred);
  }

  private static <K extends @Nullable Object, V extends @Nullable Object> void succeedsInMultimap(
      ValueEntry<K, V> pred, ValueEntry<K, V> succ) {
    pred.setSuccessorInMultimap(succ);
    succ.setPredecessorInMultimap(pred);
  }

    if (waiters == 0) {
      // unlink guard from activeGuards
      for (Guard p = activeGuards, pred = null; ; pred = p, p = p.next) {
        if (p == guard) {
          if (pred == null) {
            activeGuards = p.next;
          } else {
            pred.next = p.next;
          }
          p.next = null; // help GC
          break;
        }
      }
    }
  }

            c.g.c.base.testModule transitively pulls in .java files from both modules while reading
            the module description of only the prod module. And the prod module doesn't inherit all
            the modules that the test module classes use, so we get errors.

            The good news is that, despite ignoring errors here, GWT does fail if any errors affect

    while (true) {
      Waiter pred = null;
      Waiter curr = waiters;
      if (curr == Waiter.TOMBSTONE) {
        return; // give up if someone is calling complete
      }
      Waiter succ;
      while (curr != null) {
        succ = curr.next;
        if (curr.thread != null) { // we aren't unlinking this node, update pred.
          pred = curr;

    NodeConnection(N node) {
      this.node = checkNotNull(node);
    }

    static final class Pred<N> extends NodeConnection<N> {
      Pred(N node) {
        super(node);
      }

      @Override
      public boolean equals(@CheckForNull Object that) {
        if (that instanceof Pred) {
          return this.node.equals(((Pred<?>) that).node);
        } else {
          return false;
        }
      }