duty = $duty; } /** * Get the duty (TO or CC) * * @return int Is TO or CC * * @since 1.0.0 */ public function getDuty() : int { return $this->duty; } /** * Get the relation object * * @return Account|Group * * @since 1.0.0 */ abstract public function getRelation(); /** * {@inheritdoc} */ abstract public function jsonSerialize() : mixed; }