method AbstractChatCompletionRunner.prototype.onceimport { AbstractChatCompletionRunner } from "https://deno.land/x/openai@v4.38.0/lib/AbstractChatCompletionRunner.ts"; once<Event extends keyof Events>(event: Event, listener: ListenerForEvent<Events, Event>): thisAdds a one-time listener function for the event. The next time the event is triggered, this listener is removed and then invoked. Type ParametersEvent extends keyof EventsParametersevent: Eventlistener: ListenerForEvent<Events, Event>Returnsthisthis ChatCompletionStream, so that calls can be chained