Method once

shepherd.js/src/evented.ts:42–44

* Adds an event listener that only fires once for the given event string. * * @param {string} event * @param {Function} handler * @param ctx * @returns

(event: string, handler: AnyHandler, ctx?: unknown)

   * @returns
   */
  once(event: string, handler: AnyHandler, ctx?: unknown) {
    return this.on(event, handler, ctx, true);
  }

  /**
   * Removes an event listener for the given event string.