pocketmine\IPlayer::getName PHP Method

    public function getName();

 public function setPlayer(IPlayer $player, $rank)
 {
     $fileName = $this->plugin->getDataFolder() . "players/" . strtolower($player->getName()) . ".yml";
     $config = new Config($fileName, Config::YAML, ["name" => $player->getName(), "rank" => $rank]);
     $config->set("rank", $rank);
     $config->save(true);
 }