Participants run through the streets of the Back Bay during the 16th annual Santa Speedo Run in Boston, Massachusetts, December 12, 2015. (Photo by Brian Snyder/Reuters)

Mariachi musicians prepare to perform to celebrate the Day of the Virgin of Guadalupe outside the Basilica of Guadalupe in San Salvador, El Salvador December 11, 2015. (Photo by Jose Cabezas/Reuters)

Indonesian students wearing paper masks take part in the East Java Mask Parade in Surabaya, Indonesia, 13 December 2015. Thousands of people participate in the traditional parade to preserve the mask custom among the younger generation. (Photo by Fully Handoko/EPA)

The Jet Propulsion Lab team's RoboSimian robot turns on a valve at a simulated disaster-response course during day one of the Defense Advanced Research Projects Agency (DARPA) Robotics Challenge finals in Pomona, California, June 5, 2015. (Photo by David McNew/Reuters)

Darth Mykolaiovych Vader, who is dressed as the “Star Wars” character Darth Vader, poses for a picture as he dries his mask and helmet with a hairdryer in the bathroom of his apartments in Odessa, Ukraine, December 2, 2015. Darth Vader was bent on galactic domination, but his Ukrainian namesake enjoys more mundane pursuits: local politics, walking the family dog and a spot of embroidery. The Ukrainian citizen, who has changed his name to Darth Mykolaiovych Vader, ran for the post of local mayor in October, his political backers dressed as Stormtroopers. In his trademark black outfit, he is a regular sight around Odessa, a major port city on southern Ukraine's Black Sea coast. (Photo by Valentyn Ogirenko/Reuters)

A replica of the Wall-E character is remotely controlled with a mobile phone by Bolivian student Esteban Quispe, 17, in Patacamaya, south of La Paz, December 10, 2015. Quispe built the Wall-E robot using materials he obtained from a rubbish dump in the town located in the Andean highland region. He hopes to mechanize agriculture in Patacamaya by making use of robots that operate on solar energy, Quispe told Reuters. (Photo by David Mercado/Reuters)

Members of the Moranbong Band from North Korea wait inside the lobby of a hotel in central Beijing, China, December 11, 2015. North Korea's premier pop group, the all-girl Moranbong band formed by leader Kim Jong-Un, is electrifying audiences in China in shows aimed at harmonising out-of-tune ties between the traditional allies, reports and the venue said on December 9 – but tickets are not available to the public. (Photo by Reuters/Stringer)

Rungis is a commune in the southern suburbs of Paris, France. It is best known as the location of the large wholesale food market serving the Paris metropolitan area and beyond, the Marché d'Intérêt National de Rungis, said to be the largest food market in the world. The name Rungis was recorded for the first time in a royal charter of 1124 as Rungi Villa. Here: swordfish are sold at the fish pavilion in Rungis International food market as buyers prepare for the Christmas holiday season in Rungis, south of Paris, December 11, 2015. (Photo by Philippe Wojazer/Reuters)