vue brothers do not need a parent component to pass values, okay? Just two sibling components
 first I created a new js file eventBus.js 
 and wrote 
import Vue from "Vue"
export default new Vue;
one components
     <div class="a1">
        <button @click="start"></button>
    </div>
     import bus from "../assets/eventBus";
     
    data(){
        return{
            acc:"2"
        }
    },
   start(){
            const a1=this.mydata;
            let a2=this.acc;
            bus.$emit("userDefinedEvent",[a1,a2]);
        }
two components
    <div class="a1">
        <span>:<br/>{{aaaaaaaaaaaaaaaaa}}</span>
    </div>
    import bus from "../assets/eventBus";
     return{
            aaaaaaaaaaaaaaaaa:""
        }
    mounted(){
        const _this=this;
        bus.$on("userDefinedEvent",function(msg){
            _this.aaaaaaaaaaaaaaaaa=msg;
        })
    },
in the three parent component
  <div class="home">
        <one></one>
        <two></two>
   </div>
   
import one from "@/components/one";
import two from "@/components/two";
 components:{
        one,
        two
    }
 
 
 this enables the communication between the two sibling components, but I don"t want the parent component now. It"s just the data exchange between the two components. How can I do that? 
 because it"s all imported in the parent component, I don"t need to import it in the parent component now, it"s just a communication between the two sibling components, how can I implement it? 
