code: public ResponseBuilder addVideoAppLaunchDirective(String source, String title, String subtitle) {
          Metadata metadata = Metadata.builder()
                  .withSubtitle(subtitle)
                  .withTitle(title)
                  .build();
  
          VideoItem videoItem = VideoItem.builder()
                  .withSource(source)
                  .withMetadata(metadata)
                  .build();
          LaunchDirective videoDirective = LaunchDirective.builder()
                  .withVideoItem(videoItem)
                  .build();
  
          this.shouldEndSession = null;
          return addDirective(videoDirective);
      }
docs: Adds a VideoApp {@link LaunchDirective} to the response to play a video.
  
  @param source location of video content at a remote HTTPS location
  @param title title that can be displayed on VideoApp
  @param subtitle subtitle that can be displayed on VideoApp
  @return response builder