Law enforcement officers stand, with some turning their backs, as New York City Mayor Bill de Blasio speaks on a monitor outside the funeral for NYPD officer Wenjian Liu in the Brooklyn borough of New York January 4, 2015. Tens of thousands of law enforcement officers from across the country gathered on Sunday for the funeral of the second of two New York City policemen killed last month in an ambush that galvanized critics of Mayor de Blasio. (Photo by Shannon Stapleton/Reuters)

Online hostess Xianggong (L) and other hostesses check their pictures as they gather around the photographer while taking part in a football-themed photoshoot at a photography studio in Beijing March 4, 2015. In China's online hostessing world, men find virtual company and the women can find riches. Xianggong is one of more than 10,000 hostesses on the internet site bobo.com, a live broadcasting web platform where anyone can record themselves singing, playing piano, dancing or just chatting. (Photo by Jason Lee/Reuters)

In this photo taken on Saturday, April, 4, 2015, a bear chews on a corncob at a shelter that attracts hundreds of visitors and volunteers from around the world every year, in Kutarevo, Croatia. Over a decade ago, Ivan Crnkovic-Pavenka, a retired Croatian social worker decided to help bears become “ambassadors of the wilderness” among people and set up a unique shelter for brown bears in the idyllic mountain village of Kutarevo in central Croatia, where eight bears currently live in two huge enclosures. (Photo by Amel Emric/AP Photo)

In this September 4, 1963, file photo, a police officer carries off a demonstrator holding a Confederate flag after a group of demonstrators protested enrollment of two African-Americans at Ramsay High School in Birmingham, Ala. The Confederate battle flag has been removed from South Carolina's Statehouse grounds, in the wake of the massacre of nine African-Americans, including a state senator, at an historic black church in Charleston in June 2015. (Photo by AP Photo)

Adriana Barahona, known as "Madame Barocle", wearing clothing of the Victorian era, walks along a central avenue in San Jose, Costa Rica June 4, 2015. Barahona says she has been passionate about clothing from the era of Britain's Queen Victoria (1837-1901), and has been making and wearing them since the age of 15. REUTERS/Juan Carlos Ulate

A woman jumps into water from the roof of Murru prison, an abandoned Soviet prison, in Rummu quarry, Estonia, during hot weather July 4, 2015. During the Soviet time, Rummu quarry was used as a mining site for Vasalemma marble and most of the workforce came from among the detainees of Murru prison. When the prison closed after 1991, pumps that once kept the quarry and the prison dry were shut down, causing water to fill the quarry. It has become an unofficial and unguarded swimming and diving spot, attracting locals and tourists. (Photo by Ints Kalnins/Reuters)

Male orangutan Percy is reflected in the Sekonyer River as he reaches over to try and touch a wooden klotok boat carrying crew and tourists, in Tanjung Puting National Park, in Kalimantan (Indonesian Borneo), Indonesia, September 4, 2013. Percy is a son, born and living in the wild, of a female orangutan named Princess, a freed former captive orangutan that anthropologist Dr Birute Galdikas rescued, rehabilitated and returned to the wild. (Photo by Barbara Walton/EPA)

A couple hugs while standing near a Christmas tree made out of plastic bins and plastic hampers outside the Museum of History in Monterrey, Mexico, December 4, 2015. The humble Christmas tree has a rich history, from evergreen trees used to symbolise eternal life in Ancient Egypt to tree worship among pagan Europeans. The modern version has its origins in Germany, where the song “O Tannenbaum” is still a festive favourite. Today the traditional tree with lights and decorations appears in cities including Washington, Moscow and Beirut. Alternative constructions range from recycled rubbish in Mexico City to old window frames in Rakvere, Estonia. Whatever the shape or size, the message is the same: Merry Christmas. (Photo by Neil Hall/Reuters)