@NotNull
  private static Change readChange(@NotNull Element changeNode, @NotNull Project project) {
    FakeRevision bRev = readContentRevision(changeNode, project, RevisionSide.BEFORE);
    FakeRevision aRev = readContentRevision(changeNode, project, RevisionSide.AFTER);
    return new Change(bRev, aRev);
  }
@NotNull
  private static Change readChange(@NotNull Element changeNode, @NotNull Project project)