Add context to async example function in Network docs

Reviewed By: svcscm

Differential Revision: D2933584

fb-gh-sync-id: 24436b185791e3fa8047be521894545c08a90ee0
shipit-source-id: 24436b185791e3fa8047be521894545c08a90ee0

docs/Network.md

@@ -51,18 +51,23 @@ fetch('https://mywebsite.com/endpoint.php')
       console.warn(error);
     });
   ```
-
 2.  Called within an asynchronous function using ES7 `async`/`await` syntax:
   
   ```js
+  class MyComponent extends React.Component {
+    ...
     async getUsersFromApi() {
       try {
         let response = await fetch('https://mywebsite.com/endpoint/');
-    return response.users;
+        let responseJson = await response.json();
+        return responseJson.users;
       } catch(error) {
-    throw error;
+        // Handle error
+        console.error(error);
       }
     }
+    ...
+  }
   ```
 
 - Note: Errors thrown by rejected Promises need to be caught, or they will be swallowed silently