Law enforcement officers stand, with some turning their backs, as New York City Mayor Bill de Blasio speaks on a monitor outside the funeral for NYPD officer Wenjian Liu in the Brooklyn borough of New York January 4, 2015. Tens of thousands of law enforcement officers from across the country gathered on Sunday for the funeral of the second of two New York City policemen killed last month in an ambush that galvanized critics of Mayor de Blasio. (Photo by Shannon Stapleton/Reuters)

Muslim pilgrims pray around the holy Kaaba at the Grand Mosque, during the annual haj pilgrimage in Mecca September 30, 2014. (Photo by Muhammad Hamed/Reuters)

A solar-powered plane takes off from Jiangbei International Airport in southwest China's Chongqing Municipality, Tuesday, April 21, 2015. The Solar Impulse 2 departed Chongqing on Tuesday for a 1190-kilometer (642-mile) flight to the city of Nanjing in eastern China, the sixth leg of its around-the-world flight. (Photo by Chinatopix via AP Photo)

A passenger waits after his train arrived in Nouadhibou, Mauritania’s second largest city and the main export port for the country’s iron ore industry, on June 25, 2014. The mining company’s employees proudly call their firm the lung of their nation's economy and the train that ferries the ore to the coast stretches some two kilometres, making it one of the world's longest. SNIM mines black iron ore in the northern town of Zouerate, a remote desert location which nevertheless attracts people from all over the country looking for work. (Photo by Joe Penney/Reuters)

Noriaki Iwashima gestures as he lies in a coffin to try it out during an end-of-life seminar held by Japan's largest retailer Aeon Co in Tokyo October 24, 2014. Funeral arrangements are normally left to those who have been left behind but the latest trend in Japan, which literally translates to “End of life” preparations, is for the ageing to prepare their own funerals and graves before they set off on their journey to the great beyond. With a population that is expected to shrink by nearly 30 million people over the next 50 years, the market for funerals, graves and anything related to the afterlife is still very much alive. (Photo by Toru Hanai/Reuters)

Heavy machinery is used as Encinitas lifeguards work to remove the carcass of a large humpback whale that washed ashore in Leucadia, California, United States, July 18, 2016. (Photo by Mike Blake/Reuters)

Eurovision fans from Sweden kiss in front of the Globen Arena prior the first the Eurovision Song Contest final in Stockholm, Sweden, Saturday, May 14, 2016. (Photo by Martin Meissner/AP Photo)

A publican serves a glass of stout to a donkey in the East End of London, 1960s. (Photo by Steve Lewis/Getty Images)