Implementation Class: Data Provider Class 
The Service Builder creates an extension class for the DPC, which is the implementation class.
You can implement the methods in this class to suit your needs.
The extension class inherits from the DPC base class.
You can add your own code to specific methods for an entity set in the extension class.
Example
If you have a model for customer data and you want to implement the Get Entity operation, redefine the method, CUSTOMER_GET_ENTITY, and write your own code.
At runtime, the other generated methods in addition to your code for the CUSTOMER_GET_ENTITY method will be executed.
Implementing the Class
You redefine the methods in an extension class to suit your needs.
Recommendation
We recommend to redefine each method directly.
Caution
Changes that you make in the data model, such as, renaming, and removing of entity sets, and the attributes of entity types, which have been referenced in your code, can result in syntax errors in your implementation.