Rebel fighters from the Ahrar al-Sham Islamic Movement fire a heavy machine gun during what they said was an offensive to take the northwestern city of Idlib March 24, 2015. (Photo by Khalil Ashawi/Reuters)

A boy dressed as the Star Wars character Darth Vader attends a Star Wars themed church service, at the Zion Church in Berlin, Sunday, December 20, 2015. About 500 people, some carrying light saber props or wearing Darth Vader masks, attended the service, more than twice as many as usual on a Sunday. (Photo by Markus Schreiber/AP Photo)

A dragon mask for the upcoming Lunar New Year hangs on the wall at Lily Hambali's and lion masks and custome maker in Bogor, Indonesia, 02 February 2015. The Chinese Lunar New Year, known here as Imlek, is only three weeks away. The whole city is getting decked out to celebrate the event on 19 February 2015. (Photo by Adi Weda/EPA)

A humanoid robot named “Yangyang” shows a facial expression during its demonstration at the Global Mobile Internet Conference (GMIC) 2015 in Beijing, China, April 29, 20155. The android was produced jointly by China's Shanghai Yangyang Intellegent Robot Science Service center and Japanese professor Hiroshi Ishiguro, with the aim of popularising robotics among the young. (Photo by Kim Kyung-Hoon/Reuters)

Actor Cornelius Obonya as Jedermann and actress Brigitte Hobmeier as Buhlschaft perform on stage during a dress rehearsal of Hugo von Hofmannsthal's drama “Jedermann” (Everyman) at Domplatz square in Salzburg, Austria, July 16, 2015. The play is directed by Julian Crouch and Brian Mertes and will premiere as part of the annual Salzburg cultural Festival on July 19, 2015. (Photo by Leonhard Foeger/Reuters)

Edibles are displayed at Shango Cannabis shop on first day of legal recreational marijuana sales beginning at midnight in Portland, Oregon October 1, 2015. The sale of marijuana for recreational use began in Oregon on October 1, 2015 as it joined Washington state and Colorado in allowing the sale of a drug that remains illegal under U.S. federal law. (Photo by Steve Dipaola/Reuters)

Indonesian Presidential Security Forces (Paspampres) personnel show their skills during an anti terror exercise in Jakarta, Indonesia on 09 April 2015. The drill is in preparation for the 60th Asian-African Conference planned to be held in Jakarta from 21 to 23 April 2015. (Photo by Bagus Indahono/EPA)

A motorcyclist dodges in the annual water-splashing festival to mark the New Year of the Dai minority in Menglian, Yunnan province April 13, 2015. (Photo by Wong Campion/Reuters)