Revellers enjoy the atmosphere during the opening day or “Chupinazo” of the San Fermin Running of the Bulls fiesta on July 6, 2015 in Pamplona, Spain. The annual Fiesta de San Fermin, made famous by the 1926 novel of US writer Ernest Hemmingway entitled “The Sun Also Rises”, involves the daily running of the bulls through the historic heart of Pamplona to the bull ring. (Photo by Pablo Blazquez Dominguez/Getty Images)

A man dressed as the “Star Wars” character Darth Vader sits on a bench in central Lviv, Ukraine, November 24, 2016. (Photo by Gleb Garanich/Reuters)

A history enthusiast, dressed as a soldier, fights during the re-enactment of Napoleon's famous battle of Austerlitz near the southern Moravian town of Slavkov u Brna December 5, 2015. Hundreds of history enthusiasts gathered near the city of Slavkov before a re-enactment of Napoleon's famous battle of Austerlitz on Saturday to mark its 210th anniversary. (Photo by David W. Cerny/Reuters)

Visitors wear shirts with an image of former Chinese leader Mao Zedong at the Shanghai World Expo site in Shanghai, May 2, 2010. (Photo by Aly Song/Reuters)

A policer officer hits a man with a baton as he tries to maintain order while migrants wait for trains at a temporary camp near Gevgelija, Macedonia, September 7, 2015. Several thousand migrants in Macedonia boarded trains on Sunday to travel north after spending a night in a provisional camp. Macedonia has organised trains twice a day to the north border where migrants cross into Serbia to make their way to Hungary. Since June, Macedonian authorities have said that more than 60,000 migrants have entered the country, and around 1,500 entered just in one day, mainly refugees from Syria. (Photo by Stoyan Nenov/Reuters)

North Koreans who signed up to join the army train in the midst of political tension with South Korea, in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang August 23, 2015. Top aides to the leaders of North and South Korea resumed talks on Sunday after negotiating through the night in a bid to ease tensions involving an exchange of artillery fire that brought the peninsula to the brink of armed conflict. (Photo by Reuters/KCNA)

A “Federahannes”, a jester figure from Rottweil, participates in the “Narrensprung” (jester jump) parade in Rottweil, southern Germany, Monday, February 27, 2016. About 4000 jesters paraded through the city among thousands of spectators. The Rottweil Narrensprung is the highlight of the Swabian-Alemannic Fastnacht and one of the traditional pre-Lenten carnival parades in southwestern Germany. (Photo by Michael Probst/AP Photo)