Festivalgoers watch two actors of the Wasteland Warriors movement fight in a cage at the world's largest heavy metal festival, the Wacken Open Air 2019, in Wacken, Germany on August 3, 2019. Wacken is a village in northern Germany with a population of 1,800 that has hosted the annual festival, which attracts heavy metal fans from around the world, since 1990. (Photo by Wolfgang Rattay/Reuters)

Presentation of The work of Italian artists Antonio Garullo and Mario Ottocento, called “The Italian Dream” showing a wax figurine of Italy's former prime minister Silvio Berlusconi as being dead or asleep inside a glass shrine, is exhibited on May 29, 2012 at the Ferrajoli Palace in the center of Rome, Italy. In this controversial work Berlusconi is smiling, wearing funny slippers and the trousers open. (Photo by Alessandro Bianchi/Reuters)

People leave a giant air purifier, which its inventor calls a “super tree”, in Lima's district of Jesus Maria November 24, 2014. In Peru's notoriously polluted capital Lima, local inventor Jorge Gutierrez, a retired naval engineer, is deploying the giant air purifiers that double as billboards to suck up carbon dioxide and dangerous levels of smog. (Photo by Mariana Bazo/Reuters)

A Hot air balloon is seen at the Cup Hot Air event during the Air Sports festival titled “70 Years of Peaceful Sky” in Minsk, Belarus July 18, 2015. (Photo by Vasily Fedosenko/Reuters)

Spanish Patrulla Aguila (C-101), aerobatic demonstration team of the Spanish Air Force performs during the Radom Air Show at an airport in Radom, Poland August 23, 2015. (Photo by Kacper Pempel/Reuters)

The Screamin' Sasquatch jet powered Waco Biplane sits on display during media day for the Canadian International Air Show at Billy Bishop Airport, Toronto, Ontario, September 4, 2015. (Photo by Louis Nastro/Reuters)

An injured girl reacts at a site hit by an airstrike in the rebel-held Douma neighbourhood of Damascus, Syria November 7, 2016. (Photo by Bassam Khabieh/Reuters)

A Russian air force technician reports to a pilot that a bomber is ready for a combat mission at Hemeimeem air base in Syria Wednesday January 20, 2016. Russian warplanes have flown over 5,700 combat missions since Moscow launched its air campaign in Syria on September 30, 2015. (Photo by Vladimir Isachenkov/AP Photo)