abstract fun on(event: String, listener: Function<*>): PowerMonitor
abstract fun on(event: String, listener: Function<*>): PowerMonitor
abstract fun on(event: String, listener: Function<*>): PowerMonitor
abstract fun on(event: String, listener: Function<*>): PowerMonitor
abstract fun on(event: String, listener: Function<*>): PowerMonitor
Overrides EventEmitter.on