Method rebalance

output/java_guava/1.4.19/TreeMultiset.java:854–870

()

            }

    private AvlNode<E> rebalance() {
      switch (balanceFactor()) {
        case -2:
          if (right.balanceFactor() > 0) {
            right = right.rotateRight();
          }
          return rotateLeft();
        case 2:
          if (left.balanceFactor() < 0) {
            left = left.rotateLeft();
          }
          return rotateRight();
        default:
          recomputeHeight();
          return this;
      }
            }

    private int balanceFactor() {
      return height(left) - height(right);