Gold bars from the vault of a bank and Swiss one franc coins are seen in this illustration picture taken in Zurich November 20, 2014. The “Save our Swiss gold” proposal, spearheaded by the right-wing Swiss People's Party (SVP), aims to ban the central bank from offloading its reserves and oblige it to hold at least 20 percent of its assets in gold. The referendum is scheduled for November 30. The SVP argues it would secure a stable Swiss franc. (Photo by Arnd Wiegmann/Reuters)

An undercover police officer, who had been marching with anti-police demonstrators, aims his gun at protesters after some in the crowd attacked him and his partner in Oakland, California December 10, 2014. Police said more than 100 demonstrators marched in Berkeley, California, which has a history of social activism. Under cloudy skies, turnout was smaller than earlier in the week, when demonstrators in the area threw rocks at police and shut down a major freeway. (Photo by Noah Berger/Reuters)

The “Escape Velocity” moving sculpture by artist group Poetic Kinetics looms over Coachella festivalgoers on the Empire Polo Field, on the first day of the 2014 Coachella Music and Arts Festival in Indio, California, on April 11, 2014. (Photo by Chris Pizzello/Invision)

A man rides a motorcycle along a street in the snow in Altay, Xinjiang Uighur Autonomous region, February 9, 2016. (Photo by Reuters/Stringer)

A photo taken on July 22, 2017 shows beach- goers dancing at the West Sea Barrage beach outside the coastal city of Nampo, southwest of Pyongyang. The West Sea Barrage beach features as a stopping point for foreign tourists, and is a destination for North Korean work groups from the neighbouring area. The beach lies at the end of an eight- kilometre- long barrage that separates the sea from the Taedong River, which runs through Pyongyang. (Photo by Ed Jones/AFP Photo)

A boy shoots a World War II machine gun armed with blanks at an weapon exhibition during a military show near Kirovsk, about 30 kilometers (19 miles) east of St. Petersburg, Russia, Sunday, January 21, 2018. (Photo by Dmitri Lovetsky/AP Photo)

A member of Sakura circus team performs during the second day of a one week show in Padukka, near Colombo, Sri Lanka November 28, 2016. (Photo by Dinuka Liyanawatte/Reuters)