public Group(User user, string name, EnumNiche niche)
        {
            User  = user;
            Name  = name;
            Niche = niche;

            if (user == null)
            {
                AddNotification("Usuario", "Informe o usuário");
            }

            new AddNotifications <Group>(this).IfNullOrInvalidLength(x => x.Name, 3, 150)
            .IfEnumInvalid(x => x.Niche);
        }
 public void AlterGroup(string name, EnumNiche niche)
 {
     Name  = name;
     Niche = niche;
 }