Recycling artist Nicolas Gomez checks the strings of a cello he has made out of an oil barrel for the Orchestra of Recycled Instruments of Cateura, in Cateura, Paraguay February 13, 2015. Saudi Arabia's oil exports have risen in February in response to stronger demand from customers. As OPEC's top producer battles for market share Reuters photographers around the globe have been photographing oil barrels to document how they are utilised once the fuel has been used. (Photo by Jorge Adorno/Reuters)

Festival goers having fun at the Balaton Sound music festival in Zamardi next to the Lake of Balaton, 110 km (68 miles) west of Budapest, July 8, 2017. (Photo by Sandor Csudai)

Aiden Haas, left, and Lilli Alcala pose after being crowned Mud King and Mud Queen at the 29th annual Mud Day, Tuesday, July 12, 2016 in Westland, Mich. The event, open to children 12 and younger, was at the Hines Park-Nankin Mills Area west of Detroit. Children 12 and younger were able to slosh around in the pit while participating in mud limbo, wheelbarrow races and other free activities. (Photo by Carlos Osorio/AP Photo)

Honda MotoGP rider Dani Pedrosa (R) of Spain sprays champagne on an attendant next to Yamaha MotoGP rider Valentino Rossi (C) of Italy after winning the Japanese Grand Prix at the Twin Ring Motegi circuit in Motegi, north of Tokyo, Japan, October 11, 2015. Rossi placed second. (Photo by Issei Kato/Reuters)

Spanish actor Antonio Banderas embraces a robot used in the film Automata during a photocall on the third day of the 62nd San Sebastian Film Festival, September 21, 2014. Banderas stars in and produced the science fiction film, which is part of the festival's official section. (Photo by Vincent West/Reuters)

A resident looks into a newly-built giant trash can, partially buried underground, next to a street in Taiyuan, Shanxi province November 6, 2014. The trash can, which has a diameter of 1.9 meters and a depth of 2.8 meters, could contain approximately 10 cubic metres of garbage. It was built to replace an open-air garbage dump site, local media reported. (Photo by Reuters/Stringer)

A brown bear is checked by foreign veterinaries and local staff members at the Four Paws Bear Sanctuary in Pristina, on May 9, 2014. (Photo by Hazir Reka/Reuters)

Israeli soldiers detain a protester during a demonstration by Palestinians protesting against the Israeli-built West Bank separation barrier and calling for the right of return for Palestinian refugees, in the northern West Bank city of Tulkarem, on May 31, 2014. (AP Photo/Nasser Ishtayeh)