@Nullable
  @Override
  public Document getDocument(@NotNull PsiFile file) {
    if (file instanceof PsiBinaryFile) return null;

    Document document = getCachedDocument(file);
    if (document != null) {
      if (!file.getViewProvider().isPhysical() && document.getUserData(HARD_REF_TO_PSI) == null) {
        PsiUtilCore.ensureValid(file);
        cachePsi(document, file);
      }
      return document;
    }

    FileViewProvider viewProvider = file.getViewProvider();
    if (!viewProvider.isEventSystemEnabled()) return null;

    document = FileDocumentManager.getInstance().getDocument(viewProvider.getVirtualFile());
    if (document != null) {
      if (document.getTextLength() != file.getTextLength()) {
        String message =
            "Document/PSI mismatch: "
                + file
                + " ("
                + file.getClass()
                + "); physical="
                + viewProvider.isPhysical();
        if (document.getTextLength() + file.getTextLength() < 8096) {
          message +=
              "\n=== document ===\n" + document.getText() + "\n=== PSI ===\n" + file.getText();
        }
        throw new AssertionError(message);
      }

      if (!viewProvider.isPhysical()) {
        PsiUtilCore.ensureValid(file);
        cachePsi(document, file);
        file.putUserData(HARD_REF_TO_DOCUMENT, document);
      }
    }

    return document;
  }