import org.spongepowered.api.text.channel.MutableMessageChannel; //导入依赖的package包/类
public void awardPowerup(Player player, ItemStack held) {

    ItemStack powerup;

    Optional<String> optSuffix = SkyFeather.getSuffix(held);
    if (optSuffix.isPresent() && optSuffix.get().equals("Doom")) {
      return;
    }

    int uses = 5;
    double radius = 3;
    double flight = 2;
    double pushBack = 4;

    if (Probability.getChance(2)) {
      radius = 5;
      pushBack = 6;
    } else {
      flight = 6;
    }

    if (Probability.getChance(50)) {
      uses = -1;
      radius = 7;
      flight = 6;
      pushBack = 6;
      MutableMessageChannel targets = getPlayerMessageChannel(PlayerClassifier.SPECTATOR).asMutable();
      targets.removeMember(player);
      targets.send(Text.of(TextColors.RED, player.getName(), " has been given a Doom feather!"));

      player.getInventory().clear();
    }

    powerup = newItemStack(CustomItemTypes.SKY_FEATHER);
    SkyFeather.setFeatherProperties(powerup, uses, radius, flight, pushBack);

    player.getInventory().offer(powerup);
    tf(player).inventoryContainer.detectAndSendChanges();

    // Display name doesn't need checked as all power ups have one assigned
    player.sendMessage(Text.of(TextColors.YELLOW, "You obtain a power-up!"));
  }