title: Nodejs: firebase.auth().signInWithCustomToken(token) generate "Object has no method 'signInWithCustomToken'" error
body: <p>With new firebase version, y need to access by node.js at my firebase application.</p>
  
  <pre><code>var firebase = require("firebase");
  var parms={.......}
  firebase.initializeApp(parms);
  var token = firebase.auth().createCustomToken('123'); //Token generated successfully
  //Line below throws error
  firebase.auth().signInWithCustomToken(token).catch(function(error) {
        //do something
  });
  </code></pre>
  
  <p>If I use signInWithCustomToken from javascript in the browser, it works fine. But if I use it from command line: <i>node file.js</i>, it throws the error: <strong><em>firebase.auth().signInWithCustomToken(token) generate "Object has no method 'signInWithCustomToken'" error</em></strong></p>
  
  <p>Why?</p>