Antek Marciniec holds onto a slackline after falling off as he highlines between two cliffs at Diamond Bay on December 21, 2014 in Sydney, Australia. Slacklining is a balance sport in which participants walk on a flat nylon webbing anchored between two points with the tension adjusted to allow for slack, providing an experience similiar to that of walking on a trapmoline. Highlining is a style of slacklining where the two anchor points are set up with significant elevation from the ground or water. (Photo by Cameron Spencer/Getty Images)

Members of South Korean girl group Gfriend rehearse in Seoul December 23, 2014. Thousands of Korean children dream of becoming household names like rapper Psy, whose 2012 “Gangnam Style” video was a global YouTube hit, often putting up with punishing schedules in the hope of one day making it big in the music industry. A recent survey of pre-teens showed that 21 percent of respondents wanted to be K-pop (Korean pop) stars when they grow up, the most popular career choice. (Photo by Kim Hong-Ji/Reuters)

Thierry Reverdi, owner of the Dreamdoll company, adjusts the sunglasses of a silicone dream doll at their workshop in Duppigheim near Strasbourg, December 2, 2014. The realistic silicone s*x dolls can be ordered from a catalogue based on four hair and eye color models for a base price of 5,500 euros ($6,150). The dolls weigh around 40 kilos due to a lightweight aluminum structure and take a week to construct. The company of three employees produces some one hundred custom-made silicone s*x dolls a year, mainly for European customers. (Photo by Vincent Kessler/Reuters)

A worker makes auto parts on a machine inside a workshop in Faridabad, India, December 24, 2015. Car makers such as Maruti Suzuki India and Hyundai Motor see huge growth in India, set to become the world's third-largest auto market by 2020 as millions buy their first new car. Price tags can be as low as $3,000 for a new Tata Motors Nano mini-car. India is also becoming a low-cost export hub for global car makers such as General Motors and Ford Motor. As the sector expands, some of the work is sub-contracted out to small factories operating on paper-thin margins, where poor contract workers often have little or no access to safety equipment or health benefits. (Photo by Adnan Abidi/Reuters)

Gisele Marie, a Muslim woman and professional heavy metal musician, plays her Gibson Flying V electric guitar during a concert in Sao Paulo December 16, 2014. Based in Sao Paulo, Marie, 42, is the granddaughter of German Catholics, and converted to Islam several months after her father passed away in 2009. Marie, who wears the Burka, has been fronting her brothers' heavy metal band “Spectrus” since 2012. (Photo by Nacho Doce/Reuters)

Marion (L) and Nikola (R), members of the Sport Saber League, pose with their light sabers in front of the Eiffel tower in Paris, France, November 26, 2015. Three "Star Wars" fans opened the French Academy of the Sport Saber League in September 2015 due to the increase interest for light saber fighting and the upcoming movie "The Force Awakens" which will premier in Paris, December 16th, two days before its worldwide official release. (Photo by Charles Platiau/Reuters)

Nikolai Vasilyev, 62, dressed as Father Frost, Russian equivalent of Santa Claus, water-skis along the Yenisei River outside Siberian city of Krasnoyarsk, Russia, December 10, 2015. Vasilyev, a teacher of the Krasnoyarsk Aerospace Academy, constructed the self-made water skis to travel on the water surface. The skis are made of plastic foam and the sticks are designed to propel him forward. (Photo by Ilya Naymushin/Reuters)

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)