pocketmine\Achievement::add PHP Method

    public static function add($achievementId, $achievementName, array $requires = [])
    {
        if (!isset(Achievement::$list[$achievementId])) {
            Achievement::$list[$achievementId] = ["name" => $achievementName, "requires" => $requires];
            return true;
        }
        return false;
    }

 public function __construct(KillRatePlugin $owner, $mode)
 {
     $this->owner = $owner;
     $this->enabled = $mode;
     if ($this->enabled) {
         Achievement::add("killer", "First Blood!", []);
         Achievement::add("serialKiller", "Killer Streak!", ["killer"]);
         Achievement::add("ranked1", "Ranked #1!", ["killer"]);
         Achievement::add("kill10", "Achieved 10 Kills!", ["killer"]);
         Achievement::add("kill100", "Achieved 100 Kills!", ["kill10"]);
         Achievement::add("kill1000", "Achieved 1,000 Kills!", ["kill100"]);
     }
 }