docs: protected void ensureDJStyles() {
          //first of all, register all parent styles if any
          for (Style style : getReport().getStyles().values()) {
              addStyleToDesign(style);
          }
  
          Style defaultDetailStyle = getReport().getOptions().getDefaultDetailStyle();
  
          Style defaultHeaderStyle = getReport().getOptions().getDefaultHeaderStyle();
          for (AbstractColumn column : report.getColumns()) {
              if (column.getStyle() == null)
                  column.setStyle(defaultDetailStyle);
              if (column.getHeaderStyle() == null)
                  column.setHeaderStyle(defaultHeaderStyle);
          }
      }