code:     public FormValidation doNameFreeCheck(
              @QueryParameter("value")
              final String value) {
          if (!value.equals(name)) {
              if (PluginImpl.containsServer_(value)) {
                  return FormValidation.error("The server name " + value + " is already in use!");
              } else if (ANY_SERVER.equals(value)) {
                  return FormValidation.error("Illegal name " + value + "!");
              } else {
                  return FormValidation.warning("The server " + name + " will be renamed");
              }
          } else {
              return FormValidation.ok();
          }
      }
  
      /**
       * Generates a list of helper objects for the jelly view.
       *
       * @return a list of helper objects.
       */
  