private boolean checkIndexState(IndexDescriptor indexRule, DiffSets<IndexDescriptor> diffSet)
     throws IndexNotFoundKernelException {
   if (diffSet.isAdded(indexRule)) {
     return true;
   }
   if (diffSet.isRemoved(indexRule)) {
     throw new IndexNotFoundKernelException(
         String.format(
             "Index for label id %d on property id %d has been " + "dropped in this transaction.",
             indexRule.getLabelId(), indexRule.getPropertyKeyId()));
   }
   return false;
 }