method EventEmitter.prototype.onceRe-exportimport { EventEmitter } from "https://deno.land/x/puppeteer@16.2.0/mod.ts"; once(event: EventType, handler: Handler): EventEmitterLike on but the listener will only be fired once and then it will be removed. Like on but the listener will only be fired once and then it will be removed. Parametersevent: EventType the event you'd like to listen to handler: Handler the handler function to run when the event occurs ReturnsEventEmitterthis to enable you to chain method calls.