code: protected void addPackageList(Content contentTree) {
          Content caption = getTableCaption(configuration.getContent(
                  "doclet.ClassUse_Packages.that.use.0",
                  getLink(new LinkInfoImpl(configuration,
                          LinkInfoImpl.Kind.CLASS_USE_HEADER, typeElement))));
          Content table = (configuration.isOutputHtml5())
                  ? HtmlTree.TABLE(HtmlStyle.useSummary, caption)
                  : HtmlTree.TABLE(HtmlStyle.useSummary, useTableSummary, caption);
          table.addContent(getSummaryTableHeader(packageTableHeader, "col"));
          Content tbody = new HtmlTree(HtmlTag.TBODY);
          boolean altColor = true;
          for (PackageElement pkg : pkgSet) {
              HtmlTree tr = new HtmlTree(HtmlTag.TR);
              tr.addStyle(altColor ? HtmlStyle.altColor : HtmlStyle.rowColor);
              altColor = !altColor;
              addPackageUse(pkg, tr);
              tbody.addContent(tr);
          }
          table.addContent(tbody);
          Content li = HtmlTree.LI(HtmlStyle.blockList, table);
          contentTree.addContent(li);
      }
docs: Add the packages elements that use the given class.
  
  @param contentTree the content tree to which the packages elements will be added