old_contents: const YouTube = require('simple-youtube-api');
  const Api = new YouTube('  Y  o  u  r     A  p  i     K  e  y  ');
  
  Api.playlistById('PL2BN1Zd8U_MsyMeK8r9Vdv1lnQGtoJaSa')
      .then(results => {
          console.log(`The playlist's title is ${results[0].title}`);
      })
      .catch(console.log);
  
  
  /*
  
      - - - - - - - - - - - - - - - - - - - -
          playlistById:
  
          Parameters:
          - Playlist ID
  
          Returns:
          - Promise <Array, Error>
  
          Properties:
          - title
          - id
          - description
          - url
          - publishedAt
          - channel
            > title
            > id
  
  */
  
new_contents: const YouTube = require('simple-youtube-api');
  const Api = new YouTube('  Y  o  u  r     A  p  i     K  e  y  ');
  
  Api.playlistById('PL2BN1Zd8U_MsyMeK8r9Vdv1lnQGtoJaSa')
      .then(results => {
          console.log(`The playlist's title is ${results[0].title}`);
  
          results[0].getVideos()
              .then(videos => {
                  console.log(`This playlist has ${videos.length} videos.`);
              })
              .catch(console.log);
      })
      .catch(console.log);
  
  
  /*
  
      - - - - - - - - - - - - - - - - - - - -
          playlistById:
  
          Parameters:
          - Playlist ID
  
          Returns:
          - Promise <Array, Error>
  
          Properties:
          - title
          - id
          - description
          - url
          - publishedAt
          - channel
            > title
            > id
  
          Functions:
          - getVideos
            >  Returns:
            >  - Promise <Array, Error>
  
  */
  
subject: Add getVideos to playlistById