private void showMergeDialog(@NotNull Collection<? extends VirtualFile> initiallyUnmergedFiles) {
    TransactionGuard.getInstance().assertWriteSafeContext(ModalityState.defaultModalityState());
    ApplicationManager.getApplication().invokeAndWait(() -> {
      MergeProvider mergeProvider = new GitMergeProvider(myProject, myParams.reverse);
      AbstractVcsHelper.getInstance(myProject)
        .showMergeDialog(new ArrayList<>(initiallyUnmergedFiles), mergeProvider, myParams.myMergeDialogCustomizer);
    });
  }
private void showMergeDialog(@NotNull Collection<? extends VirtualFile> initiallyUnmergedFiles)