emitter.on('send', listener2); emitter.on('send', listener3); emitter.once('send', listener); emitter.once(1, listener4); emitter.prependListener('send', listener5); emitter.prependOnceListener('send', listener6); emitter.listeners('send'); emitter.listenerCount('send'); emitter.rawListeners('send'); EventEmitter.defaultMaxListeners = 100; console.log(`count(static): ${EventEmitter.listenerCount(emitter, 'send')}`); console.log(`ncount: ${emitter.listenerCount('send')}`); console.log(`maxListeners: ${emitter.getMaxListeners()}`); console.log(`eventNames: ${emitter.eventNames().join(', ')}`); console.log(`rawListeners count: ${emitter.rawListeners('send').length}`); setTimeout(() => { console.log('\n'); emitter.emit('send'); }, 1000); setTimeout(() => { console.log('\n');