title: Cannot read property 'channels' of undefined youtube api
body: <p>Cannot get user channel using youtube api, don't know what is going wrong. Here's my code: </p>
  
  <pre><code>ngAfterViewInit(): void {
      gapi.load('client', this.initGoogleAuthentication.bind(this));
  }
  
  initGoogleAuthentication() {
      this.socialService.getConfiguration().subscribe(this.onConfigurationLoaded.bind(this));
  }
  
  onConfigurationLoaded(operation: OperationDataResult&lt;Config&gt;) {
      if (operation &amp;&amp; operation.success) {
  
          const config = operation.model;
  
          gapi.client.setApiKey(config.youtubeSecret);
          gapi.auth.init(this.checkAuth());
  
      } else {
          console.log('failed loaded configuration ', operation);
      }
  }
  
  checkAuth() {
      gapi.auth.authorize({
              client_id: this.oAuthKey,
              scope: this.scopeLink, // https://www.googleapis.com/auth/youtube
              immediate: true
          },
          this.handlaOAuthReslult.bind(this));
  }
  
  handlaOAuthReslult(authResult) {
      if (authResult &amp;&amp; !authResult.error) {
  
          gapi.client.load('youtube',
              'v3',
              () =&gt; {
                  var request = gapi.client.youtube.channels.list({
                      mine: true,
                      part: 'id'
                  });
                  request.execute(response =&gt; {
                      let playlistId = response.result.items[0].contentDetails.relatedPlaylists.uploads;
                  });
              });
      } else {
          gapi.auth.authorize({
                  client_id: this.oAuthKey,
                  scope: this.scopeLink,
                  immediate: false
              }, this.handlaOAuthReslult.bind(this));
      }
  }
  </code></pre>
  
  <p>It falls in handlaOAuthReslult function where it have two error where executing <code>gapi.client.load</code> with error: </p>
  
  <pre><code>Request URL:https://content.googleapis.com/discovery/v1/apis/youtube/v3/rest?fields=kind%2Cname%2Cversion%2CrootUrl%2CservicePath%2Cresources%2Cparameters%2Cmethods%2CbatchPath%2Cid&amp;pp=0&amp;key=mykey
  Request Method:GET
  Status Code:400 
  </code></pre>
  
  <p>and 2nd error on executing <code>gapi.client.youtube.channels.list</code> where it tells that <code>channels</code>is undefined </p>