Ana Ivanovic of Serbia plays a backhand return to Maria Sharapova of Russia during their women's singles final match at the Brisbane International tennis tournament in Brisbane, January 10, 2015. (Photo by Jason Reed/Reuters)

A Russian air force technician reports to a pilot that a bomber is ready for a combat mission at Hemeimeem air base in Syria Wednesday January 20, 2016. Russian warplanes have flown over 5,700 combat missions since Moscow launched its air campaign in Syria on September 30, 2015. (Photo by Vladimir Isachenkov/AP Photo)

Moonfest 2012: West Palm Beach lures the undead out for a night of revelry. (Photo by Brynn Anderson/The Palm Beach Post)

Pilots plan a flight manoeuvre with model aircraft at a military air base in Vasylkiv, Ukraine, August 3, 2016. (Photo by Gleb Garanich/Reuters)

In preparation for the Dubai Duty Free Men's Open, Andre Agassi and Roger Federer of Switzerland, couldn't resist the temptation to have a friendly “hit” on the world's most unique tennis court, the Helipad of the Burj Al Arab, the world's most luxurious hotel. Standing 321 metres high on a man made island, the majestic Burj Al Arab is without doubt the most recognizable hotel in the world. The hotel's helipad, which is situated 211 metres high covers a surface area of 415 square metres. The pictures were taken on February 22, 2005, in Dubai, United Arab Emirates. (Photo by Getty Images for Dubai Duty Free)

An Iraqi soldier drives MRAP at his base in Makhmour, after it was freed from control of Islamic State, south of Mosul, April 17, 2016. (Photo by Ahmed Jadallah/Reuters)

A police officer jump ropes with a police dog at a police dog training base on July 11, 2011 in Beijing, China. The Police Dog Training Base was opened to a media visit to show the dogs skills to the public. (Photo by ChinaFotoPress/Getty Images)