Accessing battery info

Question

I seem to not find any documentation about android service wrappers and I'm stuck with "use of undeclared identificator "TJBatteryManager".

#include <Androidapi.Helpers.hpp>
#include <Androidapi.JNI.Telephony.hpp>
#include <Androidapi.JNI.Os.hpp>

...

int TGlobal::getBatteryLevel(){
    _di_JObject BatterObj = SharedActivityContext()->getSystemService(TJContext::JavaClass->BATTERY_SERVICE);
    return TJBatteryManager::Wrap(((_di_ILocalObject)BatterObj)->GetObjectID())->getIntProperty(BATTERY_PROPERTY_CAPACITY);
}

I found this syntax on some code samples and the project i'm working on already use this same process with TELEPHONY_SERIVCE and TJTelephonyManager::Wrap. Am I the one that has to create this TJBatteryManager somewhere ?

I don't find any reference of TJTelephonyManager anywhere else than in this class tho.

Same thing about _di_JXXXX types. _di_JObject and _di_JTelephonyManager are used in my project and it seems they just come from the Androidapi includes, so why is it telling me _di_JBatteryManager does not exist ?