*/
  private transient int @Nullable [] predecessor;

  /**
   * Pointer to the successor of an entry in insertion order. ENDPOINT indicates a node is the last
   * node in insertion order; all values at indices ≥ {@link #size()} are UNSET.
   */
  private transient int @Nullable [] successor;

  /** Pointer to the first node in the linked list, or {@code ENDPOINT} if there are no entries. */

        checkArgument(incidentEdge.nodeU().equals(thisNode));

        N successor = incidentEdge.nodeV();
        V value = successorNodeToValueFn.apply(successor);

        Object existingValue = adjacentNodeValues.put(successor, value);
        if (existingValue != null) {
          checkArgument(existingValue == PRED);
          adjacentNodeValues.put(successor, new PredAndSucc(value));
        }

  @CanIgnoreReturnValue
  N removeOutEdge(E edge);

  /**
   * Add {@code edge} to the set of incoming edges. Implicitly adds {@code node} as a predecessor.
   */
  void addInEdge(E edge, N node, boolean isSelfLoop);

  /** Add {@code edge} to the set of outgoing edges. Implicitly adds {@code node} as a successor. */
  void addOutEdge(E edge, N node);

    }
  }

  private static <T extends @Nullable Object> void successor(AvlNode<T> a, AvlNode<T> b) {
    a.succ = b;
    b.pred = a;
  }

  private static <T extends @Nullable Object> void successor(
      AvlNode<T> a, AvlNode<T> b, AvlNode<T> c) {
    successor(a, b);
    successor(b, c);
  }

  /*

  /**
   * Remove {@code node} from the set of successors. Returns the value previously associated with
   * the edge connecting the two nodes.
   */
  @CanIgnoreReturnValue
  @Nullable V removeSuccessor(N node);

  /**
   * Add {@code node} as a predecessor to the origin node. In the case of an undirected graph, it
   * also becomes a successor. Associates {@code value} with the edge connecting the two nodes.
   */

                      Iterators.transform(
                          // filter out 'node' from successors (already covered by predecessors,
                          // above)
                          Sets.difference(graph.successors(node), ImmutableSet.of(node)).iterator(),
                          (N successor) -> EndpointPair.ordered(node, successor))));
            } else {
              return Iterators.unmodifiableIterator(

          } else {
            firstException.addSuppressed(throwable)
          }
        }

        val nextPlan = connectResult.nextPlan
        if (nextPlan != null) {
          // Try this plan's successor before deferred plans because it won the race!
          routePlanner.deferredPlans.addFirst(nextPlan)
        }
      }
    } finally {
      cancelInFlightConnects()
    }

    throw firstException!!

      }

      for (N successor : sanityCheckSet(network.successors(node))) {
        assertThat(network.predecessors(successor)).contains(node);
        assertThat(network.edgesConnecting(node, successor)).isNotEmpty();
      }

      for (E incidentEdge : sanityCheckSet(network.incidentEdges(node))) {
        assertTrue(
            network.inEdges(node).contains(incidentEdge)

    values[size] = value;

    insertIntoTableKToV(size, keyHash);
    insertIntoTableVToK(size, valueHash);

    int successor =
        (predecessor == ENDPOINT) ? firstInInsertionOrder : nextInInsertionOrder[predecessor];
    setSucceeds(predecessor, size);
    setSucceeds(size, successor);
    size++;
    modCount++;
    return null;
  }

  /**

> Without a 'Complete' status any 'Active' or 'Draining' pool(s) are not allowed to be removed once configured.

## NOTE

- Empty delete markers (such as for objects with no other successor versions) do not transition to the new pool to avoid creating empty metadata on the other pool(s). If you believe transitioning empty delete markers is required, open a GitHub issue.

## TODO