code: public int doStartTag() throws JspException
      {
          if (hasErrors())
              return reportAndExit(SKIP_BODY);
  
          Tag parentTag = findAncestorWithClass(this, IUrlParams.class);
          if (parentTag != null) {
              // this map shouldn't be null because the attribute is required.
              assert(_map != null);
              IUrlParams parent = (IUrlParams) parentTag;
              Iterator it = _map.entrySet().iterator();
              while (it.hasNext()) {
                  Map.Entry key = (Map.Entry) it.next();
                  parent.addParameter(key.getKey().toString(), key.getValue(), null);
              }
          }
          else {
              String msg = Bundle.getString("Tags_InvalidParameterMapParent");
              registerTagError(msg, null);
              reportErrors();
          }
  
          localRelease();
          return SKIP_BODY;
      }
docs: Add each parameter in the URL parameter map to the Parameter's parent.
  @throws JspException if a JSP exception has occurred