@overridevoid didChangeAppLifecycleState(AppLifecycleState state) {
if(state == AppLifecycleState.resumed){
// user returned to our app
}else if(state == AppLifecycleState.inactive){
// app is inactive
}else if(state == AppLifecycleState.paused){
// user is about quit our app temporally
}else if(state == AppLifecycleState.suspending){
// app suspended (not used in iOS)
}
}