code: public void doInvocationCollaboratorsPreInvoke(IInvocationCollaborator[] webAppInvocationCollaborators, WebComponentMetaData cmd,
                                                   ServletRequest request, ServletResponse response)
    {
      if (webAppInvCollabs != null && !webAppInvCollabs.isEmpty())
      {
        for (WebAppInvocationCollaborator inv : webAppInvCollabs)
        {
          inv.preInvoke(cmd,request,response);
        }
      }
    }
docs: /*
  LIBERTY: collaborators are not passed through each web app but are managed within this class
  (so ignore the null arg and use the local list)