@NotNull
  public static Document createDocument(@NotNull FileType fileType, @NotNull String text, @NotNull Project project) {
    final PsiFile file =
      PsiFileFactory.getInstance(project).createFileFromText("Dummy." + fileType.getDefaultExtension(), fileType, text, -1, true);
    final Document document = PsiDocumentManager.getInstance(project).getDocument(file);
    assert document != null;
    return document;
  }
@NotNull
  public static Document createDocument(@NotNull FileType fileType, @NotNull String text, @NotNull Project project)