1. Open your command-line application and navigate to your workspace.
2. Create a new folder named 11-05-create-map-from-data.
3. Create a main.js file that defines a new class named Rocket that takes a constructor argument name and assigns it to an instance property:

// main.js 
class Rocket { 
  constructor(name) { 
    this.name = name; 
  } 
   } 

4. Create an enum of various launch sites:

// main.js 
const LaunchSite = { 
  KENNEDY_SPACE_CENTER: Symbol('Kennedy Space Center'), 
  JUIQUAN: Symbol('Jiuquan Satellite Launch Center'), 
  WHITE_SANDS: Symbol('Jiuquan Satellite Launch Center'), 
  BAIKONUR: Symbol('Baikonur Cosmodrome') 
}  

5. Create a main function. In that function, create a map with launch site and rocket key value pairs:

// main.js 
export function main() { 
  const rocketSites = [ 
    [ LaunchSite.KENNEDY_SPACE_CENTER, new Rocket('US: Saturn 
    V'),], 
    [ LaunchSite.WHITE_SANDS, new Rocket('US: Falcon Heavy') ], 
    [ LaunchSite.BAIKONUR, new Rocket('USSR: Soyuz') ], 
    [ LaunchSite.JUIQUAN, new Rocket('CN: Long March') ] ] 
 
  const rocketSiteMap = new Map(rocketSites); 
  console.log(rocketSiteMap) 
} 

6. Start your Python web server and open the following link in your browser:
   http://localhost:8000/.
7. You should see the following output: