A hooded protester throws a petrol bomb to riot policemen during clashes, following a rally marking the 43rd anniversary of a 1973 student uprising against the military dictatorship that was ruling Greece, in Athens, Greece, November 17, 2016. (Photo by Yannis Behrakis/Reuters)

A diver wearing a Santa Claus costume feeds a sunfish to attract visitors at the Hakkeijima Sea Paradise aquarium in Yokohama, suburban Tokyo on December 17, 2014. Christmas attractions will be held till Christmas Day. (Photo by Yoshikazu Tsuno/AFP Photo)

A pet owner holds his guinea pig named Riec as Father Francisco bestows a blessing on the pet rodent during a feast day Mass in honor of Saint Anthony, the patron saint of animals, at the Saint Fernando church, in Mexico City, Saturday, January 17, 2015. Many people in Mexico bring their pets to churches to be blessed by the priest on this day. (Photo by Marco Ugarte/AP Photo)

Olaf Niess catches swans on the river Alster near the town hall in Hamburg, Germany, 17 November 2015. The Alster swans are moving to their ice-free winter quarters on the Eppendorf Muehlenteich millpond until spring. (Photo by Bodo Marks/EPA)

Boats of fishermen are seen on the dried Poopo lakebed in the Oruro Department, south of La Paz, Bolivia, December 17, 2015. Lake Poopo in Bolivia, the Andean nation's formerly second largest after the famed Titicaca, has dried up entirely. With the water now gone, animals have died off in the millions, according to studies. And the local families, having lost much of their sustenance, have been forced to migrate. (Photo by David Mercado/Reuters)

An excavator removes a dead bear at the zoo in Tbilisi, Georgia, June 17, 2015. Tigers, lions, bears and wolves were among more than 30 animals that escaped from a Georgian zoo and onto the streets of the capital Tbilisi on Sunday during floods that killed at least 12 people. REUTERS/David Mdzinarishvili

A sauna building sits above the clouds at 9,280 feet (2,752 meters) at the Rifugio Lagazuoi in the Dolomite Mountains near Cortina d' Ampezzo in northern Italy July 17, 2015. The Dolomites are home to the Dolomiti Bellunesi National Park and were declared a UNESCO World Heritage Site in August, 2009. (Photo by Bob Strong/Reuters)

Xiao Jiguo, a 29-year-old actor from China's Sichuan province, reacts after shaping his eyebrows to impersonate U.S. President Barack Obama in a hotel room in the southern Chinese city of Guangzhou September 17, 2015. Xiao is taking part in the filming of a comedy film in Guangzhou, playing a low-level gangster who looks like Obama. (Photo by Bobby Yip/Reuters)