A group of people are seen on a Victoria line train in London, England during the first night of the Night Tube service on August 19 2016. The Central line and Victoria line are the first to operate a Night service with further lines expected to be running by the end of the year. (Photo by SWNS.com)

A glass is checked at the table for China's top leaders before the start of a reception to celebrate National Day at the Great Hall of the People in Beijing, China September 30, 2016. China celebrates its National Day on October 1. (Photo by Damir Sagolj/Reuters)

A participant in costume poses to a camera after a Halloween parade in Kawasaki, south of Tokyo, Japan October 30, 2016. More than 130,000 spectators turned up to watch the parade, where about 2,600 participants dressed up in costumes, according to the organiser. ((Photo by Kim Kyung-Hoon/Reuters)

A Polisario fighter sits on a rock at a forward base on the outskirts of Tifariti, Western Sahara, September 9, 2016. At a rocky outpost in Western Sahara, a new generation of soldiers who have never known war are mobilising as tensions resurface in one of Africa's oldest disputes after a quarter century of uneasy peace. (Photo by Zohra Bensemra/Reuters)

Santa Jerry Julian of Colorado Springs, Colorado hides in the grass following a ride on the Polar Express during a field trip from the Charles W. Howard Santa Claus School in Midland, Michigan, U.S. October 28, 2016. (Photo by Christinne Muschi/Reuters)

Robot inventor Wu Yulu sits on a rickshaw driven by a robot which he invented in his village in rural Beijing's Tongzhou district, China, 17 November 2016. The 54-year-old Chinese farmer living in rural Beijing's Tongzhou district invented 63 robots in the past 30 years. Wu, who only received primary school education, plans to give up the agricultural work for his robot products. He regularly participates in exhibitions, transfers patent rights and teaches at the university to earn money. (Photo by Wu Hong/EPA)

Immigrants from the West Indies at Victoria Station in London, 1956. (Photo by Hulton-Deutsch Collection/CORBIS/Corbis via Getty Images)

Tyson the Bulldog sits with reindeer antlers on Christmas Day at Central Park in Manhattan, New York City, U.S., December 25, 2016. (Photo by Andrew Kelly/Reuters)