A protester uses molotov cocktails against riot police during May Day protests on May 1, 2010 in Athens, Greece. (Photo by Milos Bicanski /Getty Images)

A six-year-old acrobat performs on the opening of a tourist festival in Bozhou, Anhui province, China May 3, 2015. (Photo by Reuters/China Daily)

Frida Karlsson takes 2nd place, Therese Johaug of Norway takes 1st place, Ingvild Flugstad Oestberg of Norway takes 3rd place during the FIS Nordic World Ski Championships Women's Cross Country Classic on February 26, 2019 in Seefeld, Austria. (Photo by Lisi Niesner/Reuters)

Yokozuna-ranked sumo wrestler Hakuho of Mongolia (top) throws Goeido of Japan during their bout on the final day of the 15-day Kyushu Grand Sumo Tournament in Fukuoka on November 26, 2017. Mongolian grand champion Hakuho won the latest sumo tournament on November 25 as Japan's national sport continued to draw media attention after another top wrestler faced a police probe into an alleged assault. He won the 15-day tournament at 13-1 by Saturday with one day remaining as his closest contenders were all defeated at 11-3 before his bout on the day. (Photo by AFP Photo/JIJI Press)

A pole-dancing robot built by British artist Giles Walker performs at a gentlemen's club Monday, January 8, 2018, in Las Vegas. The event was held to coincide with CES International. (Photo by Jae C. Hong/AP Photo)

Saraa Mutawkil (R), 18, practises boxing at Al Rabie club in Omdurman May 10, 2016. (Photo by Mohamed Nureldin Abdallah/Reuters)

Jean-Pierre Giagnoli walks through a crowded area of vendors hawking cat related goods at CatCon LA in Los Angeles, on Sunday, June 26, 2016. (Photo by Richard Vogel/AP Photo)

A Syrian refugee man (obscured) moves boxes of goods at his shop in Zaatari refugee camp near the border with Syria, in Mafraq, Jordan October 15, 2016. (Photo by Ammar Awad/Reuters)