function it_can_sum(Accountant $accountant, Money $money1, Money $money2, Money $money3, Money $money4)
{
$accountant->sum(array($money1, $money2, $money3))->willReturn($money4);
$this->sum(array($money1, $money2, $money3))->shouldReturn($money4);
}
/**
* @param Money\Money[] $monies
* @return Money\Money
*/
public function sum(array $monies)
{
return $this->accountant->sum($monies);
}