title: Property 'subscribe' does not exist on type 'void'
body: <p>I have seen the previous question but could not solve it. I am getting error while serving the ionic 2 application. Here is my code of call</p>
  
  <pre><code> updateLocation(location) {
      let userInfo;
      this.storage.get(this.CURRENT_USER_KEY)
      .then(data =&gt; {
          if (data) {
              userInfo = JSON.parse(data);
              userInfo['latitude'] = location.latitude;
              userInfo['longitude'] = location.longitude;
              return this.httpClient.post(ENDPOINTS.BASE + ENDPOINTS.UPDATE, userInfo)
              .subscribe(res =&gt; {
                  console.log('update response: ' + JSON.stringify(res));
              });
          } else {
              return null;
          }
      });
  }
  </code></pre>
  
  <p>and here I'm calling this function like this: </p>
  
  <pre><code>this.zone.run(() =&gt; {
              this.userService.updateLocation(position.coords)
              .subscribe(res =&gt; {      // here i'm getting this error
                  this.groupLocation = position.coords;
              });
          });
  </code></pre>
  
  <p>Please help.</p>