1. DomName('Geofencing.unregisterRegion')
  2. DocsEditable()
  3. Experimental()
Future unregisterRegion(String regionId)

Source 

@DomName('Geofencing.unregisterRegion')
@DocsEditable()
@Experimental() // untriaged
Future unregisterRegion(String regionId) => convertNativePromiseToDartFuture(_blink.BlinkGeofencing.instance.unregisterRegion_Callback_1_(this, regionId));