An Apple Inc., employee holds the new white iPhone 4 at the Apple store April 28, 2011 in Palo Alto, California. The long awaited white iPhone, first announced in June of 2010, went on sale worldwide for the first time today. (Photo by David Paul Morris/Getty Images)

A competitor gestures as he crawls beneath barbed wire during the Tough Guy event in Perton, central England February 1, 2015. The annual event to raise cash for charity challenges thousands of international competitors in a cross country run followed by an assault course consisting of obstacles including water, fire and tunnels. (Photo by Phil Noble/Reuters)

Two stags fight in a wildlife park in Aurach near Kitzbuehel, in the Austrian province of Tyrol. (Photo by Kerstin Joensson/Associated Press)

The Apple l, the first Apple computer made by Steve Jobs and Steve Wozniak in 1976, is seen on display at Sotheby's on June 8, 2012 in New York City. Sotheby's called the computer “an exceptionally rare, working example with original Apple cassette interface, operation manuals and a rare BASIC Users' Manual”. (Photo by Andrew Burton/AFP)

Christmas decoration selling during Depot Christmas Shopping on November 23, 2011 in Hamburg, Germany. (Photo by Christian Augustin/Getty Images)

Models wear creations by brand Leonisa during Colombiamoda fashion event in Medellin, Colombia, July 28, 2015. (Photo by Fredy Builes/Reuters)

Guillaume Rolland of France stands on the line during the Highline Extreme event in Moleson, Switzerland September 25, 2015. European best slackliners will compete until Sunday on six different lines ranging from 45 metres (148 ft) to 495 metres (1,624 ft). The 495 metres (1,624 ft) line if completed, will be the world record. (Photo by Denis Balibouse/Reuters)