Republican Presidential Candidate Donald Trump kisses his wife Melania Trump as he introduces her during first day of the Republican National Convention in Cleveland, Monday, July 18, 2016. (Photo by Matt Rourke/AP Photo)

A young man, who says he is part of a local criminal gang, poses for a picture holding a gun in the neighbourhood of Korogcho in Nairobi, Kenya, March 19, 2015. Around 2 million people live in the shantytowns packed in around Kenya's capital. Crime is high amid chronic unemployment levels, while basic services and sanitation are scarce. Residents try to make the best of things, eking out a living and picking up work where they can. (Photo by Siegfried Modola/Reuters)

Competitors in the Big Air challenge at the Proryv-2016 festival of extreme sports in Moscow, Russia on March 27, 2016. (Photo by Xinhua/Rex Features/Shutterstock)

Police walk past a burning car during riots in Birmingham City Centre on August 8, 2011 in Birmingham, England. After three nights of rioting and looting in and around London, the chaos is starting to spread to other cities around Britain. (Photo by Jeff J Mitchell/Getty Images)

Participants ride horses, hold spears and wear historic armoured suits of the Middle Ages as they compete during the Saint George international knight tournament in Moscow, Russia, May 3, 2015. (Photo by Maxim Zmeyev/Reuters)

Emily Ratajkowski arrives at The Metropolitan Museum of Art Costume Institute Benefit Gala, celebrating the opening of “Manus x Machina: Fashion in an Age of Technology” on Monday, May 2, 2016, in New York. (Photo by Charles Sykes/Invision/AP Photo)

The Tianzi Hotel with the shape of Chinese deities Fu, Lu and Shou is pictured on November 20, 2017 in Langfang, Hebei Province of China. The 41.6-meter-tall Tianzi Hotel has an exterior of Chinese Sanxing, whose names are Fu, Lu and Shou with the qualities of prosperity, status and longevity in traditional Chinese culture, in Langfang city. (Photo by VCG/VCG via Getty Images)

Leslie Cliff and his wife Violet, English figure skating pair. Olympic games of Garmisch-Partenkirchen (Germany), 1936. (Photo by Roger Viollet Collection/Getty Images)