/**
* {@inheritdoc}
*/
public function extend()
{
$now = new \Datetime();
if ($this->expiresAt < $now) {
$this->expiresAt = new \DateTime();
}
$expiresAt = clone $this->expiresAt;
$expiresAt->modify($this->increment($this->package->getSpan()));
$this->expiresAt = $expiresAt;
$this->extendedAt = new \DateTime();
}
