Employees of a food stand take pictures of Titan, a robot created by England Cyberstein Robots, performing at the Danilovsly market in downtown of Moscow, Russia, 12 May 2014. Titan visited to Moscow to attend “Bal Robotov”, an interactive exhibition of the most recent advances in robotics which will be opened on 15 May in Artplay Moscow exhibition center. Titan worked alongside superstars including Will.i.am, Rihanna, Will Smith and Jackie Chan. (Photo by Sergei Ilnitsky/EPA)

Sandra Brown, 40, rides the Skyslide on the 69th and 70th floors of the U.S. Bank Tower which is attached to the OUE Skyspace LA observation deck in downtown Los Angeles, California, U.S. June 20, 2016. (Photo by Lucy Nicholson/Reuters)

Sudanese fishermen check their boats and nets before they row through the waters of Nile River near Jebel Aulia, Sudan, May 3, 2019. (Photo by Umit Bektas/Reuters)

A man smashes an apple with a sword placed on the head of a man wearing a knave costume during the Easter knight event on April 21, 2014 in Berlin. The easter knight event delivers an insight into medieval lifestyle. (Photo by Rainer Jensen/AFP Photo/DPA)

Lu Wei-ming (L), priest of the Wei-ming temple, and a worshipper burn a Taoist paper amulet during a prayer ritual at the temple in New Taipei city January 8, 2015. The shrine, down a narrow alleyway in a bustling district of the city, is dedicated to a deity who has watched over homosexuals for four centuries. Priest Lu founded the temple in 2006, at a time gays were excluded from most religious ceremonies. (Photo by Pichi Chuang/Reuters)

Students hold their weapons before the swearing in ceremony for the military students, in Bucharest, Romania, Wednesday, October 25, 2017. The Romanian Army is proudly celebrating their Army Day and marking 100-years since the landmark battle of Marasesti, a key World War I battle in 1917 when Romanian and Russian soldiers defeated German troops, halting a German offensive. (Photo by Vadim Ghirda/AP Photo)

Humanoid robot bartender “Carl” interacts with guests at the Robots Bar and Lounge in the eastern German town of Ilmenau, July 26, 2013. “Carl”, developed and built by mechatronics engineer Ben Schaefer who runs a company for humanoid robots, prepares spirits for the mixing of cocktails and is able to interact with customers in small conversations. (Photo by Fabrizio Bensch/Reuters)

Migrants with a stick, stones and knife fight with each other after a brawl erupted over a place in an overcrowded train heading to the Serbian border at the train station in Gevgelija, The Former Yugoslav Republic of Macedonia, 14 August 2015. (Photo by Georgi Licovski/EPA/EFE)