docs: function get_player_instances(){
      var jwplayer = E.jwplayer||window.jwplayer;
      var i = 0, res = [], jw;
      // XXX marka/vadiml: a real instance will contain pause(), otherwise it
      // will be {registerPlugin: ...} with anything the customer adds
      while ((jw = jwplayer(i++)) && jw.pause)
          res.push(jw);
      return res;
  }