Workers sleep on a railway track under repair in New Delhi, India, June 15, 2018. (Photo by Saumya Khandelwal/Reuters)

A man sleeps at Beirut's Corniche, a seaside promenade, in Lebanon May 2, 2016. (Photo by Alia Haju/Reuters)

Badminton School sixth form pupils (L-R) Lucy Warden, who got 3 A* and is off to study English at Durham, Sam Crumpton, who got 1 A* and 2 A's and is off to study to be a vet at Cambridge and Madeline Sunter, who got 2 A* and 1 B, and is off to study fashion at St. Martins, celebrate their A-level results on August 18, 2011 in Bristol, England. With another record year for A-level results, sixth-form students face a scramble for university places in the final year before tuition fees rise. According to the examination bodies the pass rate rose for the 29th successive year to hit 97.8 percent, while around one in 12 exams achieved the top A* grade. (Photo by Matt Cardy/Getty Images)

An iCub robot built by the Italian Institute of Technology tracks a ball in the Robotville exhibition at the Science Museum on November 29, 2011 in London, England. The Science Museum's Robotville exhibition showcases 20 unique and cutting-edge robots from European research laboratories, it is free to enter and runs from December 1–4, 2011. (Photo by Oli Scarff/Getty Images)

International artist Yvette Mattern shows her stunning laser rainbow projection, Global Rainbow, on March 1, 2012 in Whitley Bay, England. The light installation celebrates the London 2012 Cultural Olympiad in the north-east of England. The Global Rainbow has previously lit up the skies of Germany, France and the United States. The projection will shine along the North Tyneside coastline for 4 days, before moving to other locations in the UK. (Photo by Bethany Clarke/Getty Images)

A general view of atmosphere during the NYC “Soul Train” Line Flash Mob: Hippest Trip in America in honor of Don Cornelius in Times Square on February 4, 2012 in New York City. Cornelius, the creator of “Soul Train”, died on February 1, 2012 at the age of 75. (Photo by Ilya S. Savenok/Getty Images)

Cambodian children sleep on a pavement at a park in Phnom Penh on July 8, 2016. (Photo by Tang Chhin Sothy/AFP Photo)