@TestOnly
 public void checkAllTreesEqual() {
   Collection<PsiFileImpl> roots = myRoots.values();
   PsiDocumentManager documentManager = PsiDocumentManager.getInstance(getManager().getProject());
   documentManager.commitAllDocuments();
   for (PsiFile root : roots) {
     Document document = documentManager.getDocument(root);
     PsiDocumentManagerBase.checkConsistency(root, document);
     assert root.getText().equals(document.getText());
   }
 }
  public static void renameNonCodeUsages(
      @NotNull Project project, @NotNull NonCodeUsageInfo[] usages) {
    PsiDocumentManager.getInstance(project).commitAllDocuments();
    Map<Document, List<UsageOffset>> docsToOffsetsMap = new HashMap<Document, List<UsageOffset>>();
    final PsiDocumentManager psiDocumentManager = PsiDocumentManager.getInstance(project);
    for (NonCodeUsageInfo usage : usages) {
      PsiElement element = usage.getElement();

      if (element == null) continue;
      element = CodeInsightUtilBase.forcePsiPostprocessAndRestoreElement(element, true);
      if (element == null) continue;

      final ProperTextRange rangeInElement = usage.getRangeInElement();
      if (rangeInElement == null) continue;

      final PsiFile containingFile = element.getContainingFile();
      final Document document = psiDocumentManager.getDocument(containingFile);

      final Segment segment = usage.getSegment();
      LOG.assertTrue(segment != null);
      int fileOffset = segment.getStartOffset();

      List<UsageOffset> list = docsToOffsetsMap.get(document);
      if (list == null) {
        list = new ArrayList<UsageOffset>();
        docsToOffsetsMap.put(document, list);
      }

      list.add(new UsageOffset(fileOffset, fileOffset + rangeInElement.getLength(), usage.newText));
    }

    for (Document document : docsToOffsetsMap.keySet()) {
      List<UsageOffset> list = docsToOffsetsMap.get(document);
      LOG.assertTrue(list != null, document);
      UsageOffset[] offsets = list.toArray(new UsageOffset[list.size()]);
      Arrays.sort(offsets);

      for (int i = offsets.length - 1; i >= 0; i--) {
        UsageOffset usageOffset = offsets[i];
        document.replaceString(usageOffset.startOffset, usageOffset.endOffset, usageOffset.newText);
      }
      PsiDocumentManager.getInstance(project).commitDocument(document);
    }
    PsiDocumentManager.getInstance(project).commitAllDocuments();
  }
  // need to shorten references in type argument list
  public static void shortenReference(final PsiFile file, final int offset)
      throws IncorrectOperationException {
    Project project = file.getProject();
    final PsiDocumentManager manager = PsiDocumentManager.getInstance(project);
    Document document = manager.getDocument(file);
    if (document == null) {
      PsiUtilCore.ensureValid(file);
      LOG.error("No document for " + file);
      return;
    }

    manager.commitDocument(document);
    final PsiReference ref = file.findReferenceAt(offset);
    if (ref != null) {
      PsiElement element = ref.getElement();
      if (element != null) {
        JavaCodeStyleManager.getInstance(project).shortenClassReferences(element);
        PsiDocumentManager.getInstance(project).doPostponedOperationsAndUnblockDocument(document);
      }
    }
  }