DPDP02_g3.cs

public class OpportunityRepository : IOpportunityRepository
{
    protected IOrganizationService orgService;

    public OpportunityRepository(IOrganizationService service)
    {
        this.orgService = service;
    }

    public Opportunity GetById(Guid id)
    {
        return this.orgService.Retrieve(Opportunity.EntityLogicalName, id, new ColumnSet(true))?.ToEntity<Opportunity>();
    }

    public Guid Create(Opportunity opportunity)
    {
        return this.orgService.Create(opportunity);
    }

    public void Dispose()
    {
        this.serviceContext.Dispose(); 
    }

}