private void DefineMethod()
 {
     var methodName = string.Format("<{0}>b__1", _methodInfo.Name);
     var methodBuilder = TypeBuilder.DefineMethod(methodName, MethodAttribute);
     methodBuilder.InitLocals = true;
     methodBuilder.SetParameters(new[] { _serviceType });
     methodBuilder.SetReturnType(typeof(void));
     var il = new MethodWrapper(methodBuilder);
     if (HasReturnType())
     {
         il.LoadThis();
     }
     il.LoadArgument(1);
     foreach (var parameter in _methodInfo.GetParameters())
     {
         LoadParameter(il, parameter);
     }
     il.CallVirtualMethod(_methodInfo);
     if (HasReturnType())
     {
         il.StoreToField(ResultField);
     }
     il.DoNothing();
     il.Return();
     Method = methodBuilder;
 }