docs: private void getLeafNodes(N node, List<E> result, int currentLevel) {
      // Level 1 are the leaf nodes, Level 2 is the one atop!
      if(currentLevel == 2) {
        for(int i = 0; i < node.getNumEntries(); i++) {
          result.add(node.getEntry(i));
        }
      }
      else {
        for(int i = 0; i < node.getNumEntries(); i++) {
          getLeafNodes(getNode(node.getEntry(i)), result, (currentLevel - 1));
        }
      }
    }