abstract fun addListener(event: String, listener: Function<*>): PowerMonitorabstract fun addListener(event: String, listener: Function<*>): PowerMonitorabstract fun addListener(event: String, listener: Function<*>): PowerMonitorabstract fun addListener(event: String, listener: Function<*>): PowerMonitorabstract fun addListener(event: String, listener: Function<*>): PowerMonitor