Singleton for BeaconManger

How does one make a beaconmanager a singleton in Android? I have a few activities that need to use the beaconmanager in order to start and stop nearable discovery as well as have a listener for nearables in a certain range. I was using the ShowroomManager application on the SDK examples as a rough guide. But upon debugging found that the beaconmanager had a null listener at one point and was still tracking even though I thought it stopped, which leads me to believe that I have multiple beaconmanagers running instead of just one for the application. Let me know if you’d need anything else.