ModelAPI_Session::get()->validators()->registerNotObligatory(
getKind(), SketchPlugin_SketchEntity::EXTERNAL_ID());
data()->addAttribute(SketchPlugin_Sketch::SOLVER_ERROR(), ModelAPI_AttributeString::typeId());
ModelAPI_Session::get()->validators()->registerNotObligatory(
getKind(), SketchPlugin_Sketch::SOLVER_ERROR());
ModelAPI_Session::get()->validators()->registerNotObligatory(
getKind(), SketchPlugin_SketchEntity::EXTERNAL_ID());
data()->addAttribute(SketchPlugin_Sketch::SOLVER_ERROR(), ModelAPI_AttributeString::typeId());
ModelAPI_Session::get()->validators()->registerNotObligatory(
getKind(), SketchPlugin_Sketch::SOLVER_ERROR());