如何在nodejs中将参数从一个异步函数传递给另一个异步函数？

var WebPageTest = require('webpagetest');
var wpt = new WebPageTest('url of the server');
var request = require('request');
var data_url;
var http = require('http');
var fs = require('fs');
var test_id;
var step = require('step');
step(
wpt.runTest('https://google.com', function(err, data) {
    console.log(err || data); 
    console.log('---------------');
    console.log('inside wptruntest function');
    console.log('----------------');
    data_url=data.data.summaryCSV; 
    test_id=data.data.testId;
    console.log(data_url);
    console.log('---------------');
    console.log(test_id);
    console.log('---------------');

    
}),


request(data_url, function (error, response, body) { 
       if (error) { 
      console.log(error); 
      } 
      console.log('inside request MODULE');
        console.log('---------------');
      console.log(body); 
      var data = body;
    })
);var Web