code: public void setTracks(java.util.Collection<Integer> tracks) {
          if (tracks == null) {
              this.tracks = null;
              return;
          }
  
          this.tracks = new java.util.ArrayList<Integer>(tracks);
      }
docs: Identify a track from the input audio to include in this selector by entering the track index number. To include
  several tracks in a single audio selector, specify multiple tracks as follows. Using the console, enter a
  comma-separated list. For examle, type "1,2,3" to include tracks 1 through 3. Specifying directly in your JSON job
  file, provide the track numbers in an array. For example, "tracks": [1,2,3].
  
  @param tracks
  Identify a track from the input audio to include in this selector by entering the track index number. To
  include several tracks in a single audio selector, specify multiple tracks as follows. Using the console,
  enter a comma-separated list. For examle, type "1,2,3" to include tracks 1 through 3. Specifying directly
  in your JSON job file, provide the track numbers in an array. For example, "tracks": [1,2,3].