You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: playlists_controller.rb
    path of file: ./repos/phishin/app/controllers
    
    the code of the file until where you have to start completion: class PlaylistsController < ApplicationController
  EMPTY_PLAY
    
  def unbookmark
    if current_user &&
       params[:id] &&
       (bookmark = PlaylistBookmark.find_by(playlist_id: params[:id], user: current_user))
      bookmark.destroy
      return render json: { success: true, msg: 'Playlist unbookmarked' }
    end