private static void clinit() {
    _disabled = true;
    final ArrayList<Package> list = new ArrayList<Package>();
    for (final Package p : Package.getPackages())
      if (p.getName().startsWith("net.minecraft.server"))
        list.add(p);
    if (list.size() == 1) {
      _minecraft = list.get(0).getName();
      _craftbukkit = "org.bukkit.craftbukkit" + _minecraft.substring(20);
      if (Package.getPackage(_craftbukkit) == null)
        _log.severe("[NBTLib] Can't find Craftbukkit package! (" + _minecraft
            + "/" + _craftbukkit + ")");
      else {
        _minecraft += ".";
        _craftbukkit += ".";
        _disabled = false;
      }
    } else {
      _log.severe("[NBTLib] Can't find Minecraft package! " + list.size()
          + " possible packages found:");
      for (final Package p : list.toArray(new Package[0]))
        _log.severe("[NBTLib] " + p.getName());
    }
  }