public ICollection <Account> RemoveAccountsFromClient(Client client, ICollection <Account> accounts)
{
accounts = RemoveNULL <Account> .DelNull(accounts);
client.accounts.Except(client.accounts.Intersect(accounts, new AccountComparer()));
return(client.accounts);
}
public ICollection <Account> AddAccountsToClient(Client client, ICollection <Account> accounts)
{
client.accounts.Concat(accounts.Except(client.accounts.Intersect(RemoveNULL <Account> .DelNull(accounts), new AccountComparer())));
return(client.accounts);
}