void removeRegionFromTree(@NotNull FoldRegionImpl region) {
    ThreadingAssertions.assertEventDispatchThread();
    if (!myEditor.getFoldingModel().isInBatchFoldingOperation()) {
      LOG.error("Fold regions must be added or removed inside batchFoldProcessing() only.");
    }
    onFoldProcessingStart();
    myRegionTree.removeInterval(region);
    removeRegionFromGroup(region);
  }
void removeRegionFromTree(@NotNull FoldRegionImpl region)