People are reflected in mirrors as they walk in a busy shopping district in Tokyo, Japan, December 25, 2015. (Photo by Thomas Peter/Reuters)

Members of Libyan forces allied with the UN-backed government fire a weapon towards Islamic State militants in neighbourhood Number One in central Sirte, Libya August 28, 2016. (Photo by Ismail Zitouny/Reuters)

The giant metal structure sits 330ft above the ground on the roof of a 22 storey office block in Dutch capital Amsterdam on September 6, 2016. Tourists sit in a playground-style chair as they propel themselves them over the edge of the building with only thin-air between them and the ground below. Engineers spent several years designing and building the breathtaking swing. By being fixed to the top of a building it reaches new heights – dwarfing other swings around Europe but trailing behind the 1,150ft high mechanical rides at the Stratosphere Hotel in Las Vegas, Nevada. (Photo by Huub Zeeman/SWNS.com)

Gas-masked men of the British Machine Gun Corps with a Vickers machine gun during the first battle of the Somme, 1916. (Photo by General Photographic Agency/Getty Images)

New York Sports Club Gets In The Election Spirit With Hillary Clinton And Donald Trump Boxing Inspired Class on October 27, 2016 in New York City. (Photo by Thos Robinson/Getty Images for DKC for New York Sports Clubs)

Waves hit the seawall during heavy seas and high winds in Dawlish in south west Britain, February 2, 2017. (Photo by Toby Melville/Reuters)

Elementary school children play outside their classrooms as mount Sinabung volcano spews thick volcanic ash in the background on February 10, 2017 in Karo, Indonesia. Mount Sinabung is one of the most active volcanoes in Indonesia and last erupted in May 2016, killing seven people. (Photo by Albert Damanik/Barcroft Images)

A Femen activist is led away by French police in Henin-beaumont, northern France, Sunday, May 7, 2017. Voters across France are choosing a new president in an unusually tense and important election that could decide Europe's future, making a stark choice between pro-business progressive candidate Emmanuel Macron and far-right populist Marine Le Pen. (Photo by Francois Mori/AP Photo)