method EventEmitter.listenerCountEventEmitter.listenerCount<K>(eventName: Key<K, T>,listener?: Listener2<K, T>,): numberDeprecatedReturns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event. Type ParametersKParameterseventName: Key<K, T>The name of the event being listened for optionallistener: Listener2<K, T>The event handler function Return Typenumber