private IPermissionAuthority getPermissionAuthority() {
   if (permissionAuthority == null && object instanceof EObject) {
     Session session = new EObjectQuery((EObject) object).getSession();
     if (session != null) {
       ModelAccessor modelAccessor = session.getModelAccessor();
       if (modelAccessor != null) {
         permissionAuthority = modelAccessor.getPermissionAuthority();
       }
     }
   }
   return permissionAuthority;
 }
 private IPermissionAuthority getPermissionAuthority() {
   final ModelAccessor accessor =
       SiriusPlugin.getDefault().getModelAccessorRegistry().getModelAccessor(diagram);
   return accessor.getPermissionAuthority();
 }