// Adding the class hashCode to avoid a clash with Succ instances.
        return Pred.class.hashCode() + node.hashCode();
      }
    }

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

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

	}
	metrics := globalTierMetrics.Report()
	var succ, fail float64
	for _, metric := range metrics {
		switch metric.Description.Name {
		case tierRequestsSuccess:
			succ += metric.Value
		case tierRequestsFailure:
			fail += metric.Value
		}
	}
	if int(succ) != expSuccess {
		t.Fatalf("Expected %d successes but got %f", expSuccess, succ)
	}
	if int(fail) != expFailure {

    }
  }

  for (auto succ : GetSuccessors(op)) {
    if (is_cluster_op && !IsTpuRegularOp(succ) && has_cluster_metadata) {
      if (!CheckReplicatedIOOp(succ, metadata_map[cluster], op)) return false;
    }
    if (is_cluster_op && IsTpuRegularOp(succ)) {
      if (!CheckClusterSuccessors(succ, cluster, op, metadata_map))
        return false;
    }
    if (!is_cluster_op) {

  }

  private void setSuccessor(int entry, int succ) {
    long succMask = (~0L) >>> 32;
    links[entry] = (links[entry] & ~succMask) | (succ & succMask);
  }

  private void setPredecessor(int entry, int pred) {
    long predMask = (~0L) << 32;
    links[entry] = (links[entry] & ~predMask) | ((long) pred << 32);
  }

  private void setSucceeds(int pred, int succ) {
    if (pred == ENDPOINT) {

    } else {
      setSuccessor(pred, succ);
    }

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

  @Override
  void insertEntry(
      int entryIndex, @ParametricNullness K key, @ParametricNullness V value, int hash, int mask) {
    super.insertEntry(entryIndex, key, value, hash, mask);
    setSucceeds(lastEntry, entryIndex);

  private void setSuccessor(int entry, int succ) {
    requireSuccessors()[entry] = succ + 1;
  }

  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;

  private void setSuccessor(int entry, int succ) {
    requireSuccessors()[entry] = succ + 1;
  }

  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 {
      setSuccessor(pred, succ);
    }

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

  @Override
  void insertEntry(
      int entryIndex, @ParametricNullness K key, @ParametricNullness V value, int hash, int mask) {
    super.insertEntry(entryIndex, key, value, hash, mask);
    setSucceeds(lastEntry, entryIndex);

    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);
    }

    int count(Comparator<? super E> comparator, @ParametricNullness E e) {

				// each predecessor p of n becomes a predecessor of s.
				for s := range n.succ {
					// ignore self-cycles
					if s != n {
						p.succ.add(s)
						s.pred.add(p)
					}
				}
				delete(p.succ, n) // remove edge to n
			}
		}
		for s := range n.succ {
			delete(s.pred, n) // remove edge to n
		}
	}

	// fill in index and ndeps fields