WIP dependency Injection

DaSaSo.Domain/Services/ClientServices/IClientService.cs

@@ -0,0 +1,16 @@
+using DaSaSo.Domain.Model;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace DaSaSo.Domain.Services.ClientServices
+{
+    public interface IClientService
+    {
+        Task<Client> ListAllClient();
+        Task<Client> GetClientById(int id);
+        Task<bool> CreateNewClient(string firstname, string lastname, string street, string country, string postcode);
+    }
+}