Andrea Petkovic of Germany in action against Sara Errani of Italy during day one of the Mutua Madrid Open tennis tournament at the Caja Magica on May 3, 2014 in Madrid, Spain. (Photo by Julian Finney/Getty Images)

A team of ten acrobats form the shape of a racehorse crossing the winning post ridden by Stefanie Hofer to celebrate the upcoming Dubai Duty Free Shergar Cup at Ascot Racecourse on July 29, 2014 in Ascot, England. The Dubai Duty Free Shergar Cup is the only team-format raceday in the UK and takes place on 9th August. (Photo by Ian Gavan/Getty Images for Ascot Racecourse)

“Shortly after he arrived, Van Agtmael witnessed the aftermath of this suicide bombing at a cafe that soldiers frequented in Mosul. Nine people died and 23 were wounded”. (Photo and caption by Van Agtmael/Harrison Jacobs/Magnum Photos)

A woman smokes a mask bong on the final day of Hempfest, Seattle's annual gathering to promote the legalization of marijuana, on August 17, 2014. (Photo by Jordan Stead/Seattlepi.com)

An Army Sikorsky VH-34s Choctaw helicopter once used to transport President Dwight D. Eisenhower sits in a field at the 309th Aerospace Maintenance and Regeneration Group boneyard Thursday, May 14, 2015 at Davis-Monthan Air Force Base in Tucson, Ariz. President Eisenhower became the first chief executive to be transported by helicopter. Presidents Eisenhower and John F. Kennedy were transported in VH-34 helicopters and VH-34's served as “Army One” from 1958 through 1963. (Photo by Matt York/AP Photo)

Jason Garcia poses as The Joker from Batman at the 2015 Comic-Con International in San Diego, California, July 9, 2015. (Photo by Sandy Huffaker/Reuters)

Waura Indians wrestle during this year's “quarup”, a ritual held over several days to honour in death a person of great importance to them, in Xingu National Park, Mato Grosso State, Brazil August 25, 2013. (Photo by Ueslei Marcelino/Reuters)

A dancer waits to perform during festivities marking the start of the annual harvest festival of “Onam” in Kochi, India, August 19, 2015. The ten-day-long Hindu festival is celebrated annually in India's southern coastal state of Kerala to commemorate the return of King Mahabali to his beloved subjects. (Photo by Sivaram V/Reuters)