You heard that Model should always create by using ModelService like
EmployeeModel employeModel = ModelService.create(EmployeeModel.class);
But you also use creation of model by using NEW keyword but for some specific condition and purpose . lets suppose you need to fetch model from DB then generally you will flexible search query but you do not to write query then in that case you can do as below
Above can also achieve by using ModelByExample of FlexibleSearchService as below
B2BCustomerModel customerModel = new B2BCustomerModel();
customerModel = getFlexibleSearchService().getModelByExample(customerModel);
In above code your customerModel automatically attach to model fetch by flexible search service . more or less it seems like detach in hibernate.