code: public AudioSelector withTracks(Integer... tracks) {
          if (this.tracks == null) {
              setTracks(new java.util.ArrayList<Integer>(tracks.length));
          }
          for (Integer ele : tracks) {
              this.tracks.add(ele);
          }
          return this;
      }
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].
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setTracks(java.util.Collection)} or {@link #withTracks(java.util.Collection)} if you want to override the
  existing values.
  </p>
  
  @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].
  @return Returns a reference to this object so that method calls can be chained together.