id; } public function setId(?int $id) : void { $this->id = $id; } public function getIdentifier() : string { return $this->identifier; } public function setIdentifier(string $identifier) : void { $this->identifier = $identifier; } public function getAcquired() : DateTime { return $this->acquired; } public function setAcquired(DateTime $acquired) : void { $this->acquired = $acquired; } public function getExpires() : ?DateTime { return $this->expires; } public function setExpires(?DateTime $expires) : void { $this->expires = $expires; } public function getReleased() : ?DateTime { return $this->released; } public function setReleased(?DateTime $released) : void { $this->released = $released; } }