You might have already seen that the develop branch of the Magento 2 repo contains load and save methods from Magento\Framework\Model\AbstractModel that are deprecated. If you follow the guidelines that the core module does, you may face a problem: it is necessary to use something instead of them or extend something else. Below, we provide the solution.
The most obvious solution is to use Module Service Contract – ProductRepositoryInterface for products. Alternatively, you can save entities via ResourceModel if Module Service Contract is unavailable.
From 2.1, Magento is using the EntityManagerclass to replace the inheritance. For further information, follow this link Magento 2.1 entity manager.