Revellers use water guns as they participate in a water fight during Songkran Festival celebrations at Kowloon City district, known as Little Thailand as there is large number of restaurants and shops run by Thais, in Hong Kong April 12, 2015. The Songkran festival, also known as the water festival, marks the start of Thailand's traditional New Year and is believed to wash away bad luck. (Photo by Tyrone Siu/Reuters)

Revelers, covered in coloured powder, celebrate, during a Holi Run Festival in Madrid, Spain, Sunday, April 12, 2015. Thousands of revelers took part in the festival that includes a mini marathon. The festivals are fashioned after the Hindu spring festival Holi, which is mainly celebrated in the north and east of India. (Photo by Andres Kudacki/AP Photo)

A woman rides the world's longest urban zip line, with a speed of up to 80 kilometers per hour on a one kilometer run from 170 meter to ground level, in the Marina district of Dubai, United Arab Emirates, Tuesday, December 5, 2017. (Photo by Kamran Jebreili/AP Photo)

Ryon Healy #25 of the Oakland Athletics is covered in water by Adam Rosales #16 after he hit a walk-off home run in the ninth inning against the Detroit Tigers at Oakland Alameda Coliseum on May 7, 2017 in Oakland, California. (Photo by Ezra Shaw/Getty Images)

A man who was set on fire by people accusing him of stealing during a rally against Venezuela's President Nicolas Maduro runs amidst opposition supporters in Caracas, Venezuela, May 20, 2017. (Photo by Marco Bello/Reuters)

Carnival revellers dressed as “Peliqueiros” run along a street in the village of Laza, Spain February 11, 2018. “Peliqueiros”, or ancient tax collectors, pursued villagers through the streets ringing their cowbells and hitting villagers with their sticks. (Photo by Miguel Vidal/Reuters)

People visit the autonomous urban concept car Renault EZ-GO during the first press day of the Geneva International Motor Show on March 6, 2018 in Geneva. The show opens to the public on March 8 and runs through March 18. (Photo by Fabrice Coffrini/AFP Photo)

A robot is seen on Mount Etna, Italy on July 4, 2017. Mount Etna, in Sicily, is a test bed for the approximately three-foot high, four-wheeled machine ahead of a future mission to the moon. It is being conducted by the German Aerospace Centre, the agency which runs Germany's space programme. (Photo by Antonio Parrinello/Reuters)