public WelcomeWindowViewModel(
     Authenticator authenticatorServ, 
     FriendsService friendsServ,
     UserSearcher userSerchingServ,
     Services.UserValidationService valServ)
 {
     authenticatorService = authenticatorServ;
     friendsService = friendsServ;
     userValidationService = valServ;
     userSerchingService = userSerchingServ;
 }
 public WelcomeWindowViewModel(
     Authenticator authenticatorServ,
     FriendsService friendsServ,
     UserSearcher userSerchingServ,
     Services.UserValidationService valServ)
 {
     authenticatorService  = authenticatorServ;
     friendsService        = friendsServ;
     userValidationService = valServ;
     userSerchingService   = userSerchingServ;
 }