let getEmitter function apply (ctx, method, args) { return ctx[method].apply(ctx, args) } export function $on () { return apply(getEmitter(), '$on', [...arguments]) } export function $off () { return apply(getEmitter(), '$off', [...arguments]) } export function $once () { return apply(getEmitter(), '$once', [...arguments]) } export function $emit () { return apply(getEmitter(), '$emit', [...arguments]) } export default function initEventBus (getGlobalEmitter) { getEmitter = getGlobalEmitter }