code: public void executeNext() {
  
          if (!m_idle) {
              if (m_actions.isEmpty()) {
                  m_idle = true;
              } else {
                  CmsValidationController action = m_actions.removeFirst();
                  action.internalStartValidation();
              }
          } else {
              assert false; // this shouldn't happen
          }
      }
docs: This method should be called by the validation controller when it has finished running.<p>
  
  It will execute the next validation if there is one.<p>