public bool Contains(Trainer trainer)
{
return(this.trainersById.ContainsKey(trainer.Id));
}
public bool Contains(Trainer trainer)
{
return(trainers.ContainsKey(trainer));
}
GetTrainerMembersSortedByRegistrationDateThenByNames(Trainer trainer)
{
return(trainer.Members.OrderBy(m => m.RegistrationDate).ThenBy(m => m.Name));
}