hubs/src/protocol.js

``` Caryl ------ courier3 / \ / \ courier1 courier2

class Protocol{
    constructor(){
        this.requestors = Object.create(null)
        this.prepares = Object.create(null)
    }

    registerRequestor({name, realize, prepare}){
        this.requestors[name] = realize
        prepare && (this.prepares[name] = prepare)
    }

    use(name, config){
        this.prepares[name] && this.prepares[name](config)
        return this.requestors[name]
    }
}



module.exports = new Protocol()