How i get and change an Object Integer located in ForgeData.PlayerPersisted ?

[RafaelrainBR]

Hello. I'm learning to use the Api of PowerNBT, and i have a issue. I'm using Dragon Block C, and i want to make a plugin to get the body of the player. But i'm with a lot of errors
`public class CommandTest implements CommandExecutor{

@Override
public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
	Player p = (Player)sender;
	if(cmd.getName().equalsIgnoreCase("getBody")) {
		if(p.hasPermission("admin.getbody")) {
			if(args.length >= 1 ) {
				Player t = Bukkit.getPlayer(args[0]);
				GetBody(t, sender);
				return true;
			}
		}
	}
	return false;
}

public void GetBody(Player t, CommandSender sender) {
	NBTManager manager = PowerNBT.getApi();
	NBTCompound playerData = manager.read(t);
	int Body = (int) playerData.get("ForgeData.PlayerPersisted.jrmcBodyI");
	sender.sendMessage("§eHello! The player §f" + t.getName() + " §ehas §5" + Body + " §eOf Body");
}`

And the line with errors, is this:
int Body = (int) playerData.get("ForgeData.PlayerPersisted.jrmcBodyI");

[14:35:09] [Server thread/INFO]: RafaelLocoDeCafe issued server command: /getbody RafaelLocoDeCafe [14:35:09] [Server thread/ERROR]: null org.bukkit.command.CommandException: Unhandled exception executing command 'getbody' in plugin jrmca2 v1.0 at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[PluginCommand.class:1.7.10-R0.1-SNAPSHOT] at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:181) ~[SimpleCommandMap.class:1.7.10-R0.1-SNAPSHOT] at org.bukkit.craftbukkit.v1_7_R4.CraftServer.dispatchCommand(CraftServer.java:717) ~[CraftServer.class:1.7.10-R0.1-SNAPSHOT] at net.minecraft.network.NetHandlerPlayServer.func_147361_d(NetHandlerPlayServer.java:1317) [nh.class:?] at net.minecraft.network.NetHandlerPlayServer.func_147354_a(NetHandlerPlayServer.java:1099) [nh.class:?] at net.minecraft.network.play.client.C01PacketChatMessage.func_148833_a(C01PacketChatMessage.java:38) [ir.class:?] at net.minecraft.network.play.client.C01PacketChatMessage.func_148833_a(C01PacketChatMessage.java:53) [ir.class:?] at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:245) [ej.class:?] at net.minecraft.network.NetworkSystem.func_151269_c(NetworkSystem.java:173) [nc.class:?] at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:991) [MinecraftServer.class:?] at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:431) [lt.class:?] at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:809) [MinecraftServer.class:?] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:669) [MinecraftServer.class:?] at java.lang.Thread.run(Unknown Source) [?:1.8.0_201] Caused by: java.lang.NullPointerException at com.Rafaelzin.Jrmca2.CommandTest.GetBody(CommandTest.java:33) ~[?:?] at com.Rafaelzin.Jrmca2.CommandTest.onCommand(CommandTest.java:22) ~[?:?] at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[PluginCommand.class:1.7.10-R0.1-SNAPSHOT] ... 13 more

If anyone can give me a quick help there, I need the work for this week. Thank you!