DUBAI, UNITED ARAB EMIRATES - FEBRUARY 28:  Roger Federer of Switzerland holds the trophy with the ball boy after winning the final match against Novak Djokovic of Serbia during men's singles Final match of the ATP Dubai Duty Free Tennis Championships at the Dubai Duty Free StadiumÊon February 28, 2015 in Dubai, United Arab Emirates.  (Photo by Amin Mohammad Jamali/Getty Images)