public Account(AccountId id, string holder)
{
if (holder.Trim().Length == 0)
throw new ArgumentException("Account Holder name cannot be empty", nameof(holder));
this.Id = id;
this.Holder = holder;
}
public AccountOpened(AccountId id, string holder)
{
this.SortCode = id.SortCode;
this.AccountNumber = id.AccountNumber;
this.Holder = holder;
}