code: void setSuffixLink(Node<I, S> node) {
          if (isNotFirstInsert()) {
              lastNodeInserted.setSuffixLink(node);
          }
          lastNodeInserted = node;
      }
docs: Sets the suffix link of the last inserted node to point to the supplied
  node. This method checks the state of the step and only applies the
  suffix link if there is a previous node inserted during this step. This
  method also set the last node inserted to the supplied node after
  applying any suffix linking.
  
  @param node The node to which the last node inserted's suffix link should
  point to.