text: /* @flow */
  
  import { mergeOptions } from '../util/index'
  
  export function initMixin (Vue: GlobalAPI) {
  
    // NOTE: CORE FUNCTION mixin
    // QUESTION: CORE 这里的 this 是谁
    Vue.mixin = function (mixin: Object) {
      this.options = mergeOptions(this.options, mixin)
      return this
    }
  }
  