Women in costumes walk as they participate in Halloween celebrations in the downtown of Seoul, South Korea, October 31, 2015. (Photo by Kim Hong-Ji/Reuters)

A staff member (R) looks on next to a cake, which was baked in the shape of a muscular man, for customers to try for free during a promotional event of a cake store in Shenyang, Liaoning province, China, December 6, 2015. (Photo by Reuters/Stringer)

New York City Deputy Police Commissioner John A. Leach, right, watching agents pour liquor into sewer following a raid during the height of prohibition, circa 1921. (Photo by Tom Marshall/Mediadrumworld)

A man prepares his kite to fly during an international kite festival in Alcochete, near Lisbon, Portugal, Sunday, June 28, 2015. Teams from Spain, US, Britain, Italy, France and Portugal performed with their kites during two days on the 13th edition of the event. (Photo by Francisco Seco/AP Photo)

People look at a RoboThespian humanoid robot at the Tami Intelligence Technology stall at the WRC 2016 World Robot Conference in Beijing, China, October 21, 2016. The conference showcased China's burgeoning robot industry as the nation seeks to increase the use of robots in its manufacturing and service industries. (Photo by Thomas Peter/Reuters)

Customers clink their cups as they sit in Crazy Toilet Cafe in central Moscow, Russia October 30, 2015. A new Moscow cafe, opened on Friday, serves food to its guests with crockery designed to look like small baths and urinals, in toilet-themed interior with seats resembling toilets, local media reported. (Photo by Sergei Karpukhin/Reuters)

A man holds his scythe during the Harvest Festival in Hosszuheteny, Hungary, July 9, 2016. (Photo by Laszlo Balogh/Reuters)

A soldier stands guard on the aircraft park of the Pyongyang Airport on April 3, 2011 in Pyongyang, North Korea. Pyongyang is the capital city of North Korea and the population is about 2,500,000.