docs: protected final CachedNode node() throws ItemNotFoundException, InvalidItemStateException {
          CachedNode node = sessionCache().getNode(key);
          if (node == null) {
              if (sessionCache().isDestroyed(key)) {
                  throw new InvalidItemStateException("The node with key " + key + " has been removed in this session.");
              }
              throw new ItemNotFoundException("The node with key " + key + " no longer exists.");
          }
          return node;
      }