title: node-fetch returned undefined values
body: <p>I'm trying to write a code about GTFS with node-fetch. When I use the promise, It can return values but when I try to add them into an array for information filtering purposes. The system returned undefined values. What can I do with this situation?</p>
  
  <pre><code>function getStopInfo(StopId){
  
          mta.schedule(StopId).then(function (result) {
                  console.dir(result, {depth:null, colors:true});});
  }
  
  global.info = getStopInfo('627');    
  global.a = Array(20).fill(info);    
  console.log(global.a);
  </code></pre>
  
  <p>Here are the return values:</p>
  
  <pre><code>[ undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined,
    undefined ]
  </code></pre>