Mock relationships in Apex - 04 of 05

DataLayerHandler_Test.cls

@isTest
private class DataLayerHandler_Test {

    private static MockDataLayer dataLayer;

    public class MockDataLayer implements DataLayerHandler.IDataLayer {

        List<Account> documentAccounts = new List<Account>();
        List<Document__c> mockDocuments = new List<Document__c>();

        List<Document__c> getDocumentList(){
            return mockDocuments;
        }

    }
}