关于vue实例 初始化发生了什么

function Vue (options) {
     if (process.env.NODE_ENV !== 'production' &&!(this instanceof Vue)) {
         warn('Vue is a constructor and should be called with the `new` keyword')
     }
     this._init(options)
}

initMixin(Vue)
stateMixin(Vue)
eventsMixin(Vue)
lifecycleMixin(Vue)
renderMixin(Vue)

export default Vue