code: function getObject(ctx, key) {
    if (ctx.state && (key in ctx.state)) {
      return ctx.state
    }
  
    if (key in ctx.request) {
      return ctx.request
    }
  
    if (key in ctx.req) {
      return ctx.req
    }
  
    if (key in ctx) {
      return ctx
    }
  
    return undefined
  }
docs: test where the key is available, either in `ctx.state`, Node's request, Koa's request or Koa's context