rfid sdk

[Android ] RFIDReaderAppeared event not detect

I develop RFID Reader App for Android, and have created following code

```:kotlin
class RFIDHandler(context: Context) : Readers.RFIDReaderEventHandler {
private val readers = Readers(context, ENUM_TRANSPORT.BLUETOOTH)
init {
Readers.attach(this)
}
override fun RFIDReaderAppeared(device: ReaderDevice?) {
// my processing here
}