docs: @Override
    public void initializeFromFile(TreeIndexHeader header, PageFile<N> file) {
      super.initializeFromFile(header, file);
      // compute height
      this.height = computeHeight();
  
      if(getLogger().isDebugging()) {
        getLogger().debugFine(new StringBuilder(100).append(getClass()) //
            .append("\n height = ").append(height).toString());
      }
    }