A pro-Russian rebel guards a captured former Ukrainian Army checkpoint outside Vuhlehirsk, Donetsk region, eastern Ukraine, Thursday, February 5, 2015. The rebels have closed in around the town in a strategy they triumphantly refer to as the Debaltseve cauldron. Separatists recently burst through government lines in the rural settlement of Vuhlehirsk. (Photo by Vadim Braydov/AP Photo)

Men are held by Iraqi national security agents, to be interrogated at a checkpoint, as oil fields burn in Qayara, south of Mosul, Iraq, Saturday, November 5, 2016. Islamic State fighters launch counterattacks in the thin strip of territory Iraqi special forces have recaptured in eastern Mosul, highlighting the challenges ahead as the battle moves into more densely populated neighborhoods where coalition air power must be used more selectively. (Photo by Felipe Dana/AP Photo)

Heidi Klum (not pictured) was greeted by half-naked models arriving at Myer Melbourne on January 27, 2016 in Melbourne, Australia. The supermodel continued her tour of the country promoting her new season of lingerie for Heidi Klum intimates, a brand which she took over from Elle Macpherson in 2014. (Photo by Robert Cianflone/Getty Images)

New lovebirds boxer Robin Deakin – once known as “Britain's Worst Boxer” – and former UK “Big Brother” star Lisa Appleton go to the boxing gym in London, United Kingdom on September 28, 2016. The pair were seen holding hands in the street on arrival, and they then slogged it out in the ring and fooled about in Robin's gym. (Photo by FameFlynet UK)

An urban fox walks alongside the Mall in central London, Britain, November 29, 2016. (Photo by Toby Melville/Reuters)

A prisoner from the Pedrinhas prison is carried to receive medical help after he was injured during a fight between rival gangs inside the jail, in Sao Luiz, capital of Maranhao state, January 8, 2014. The recent posting on a major Brazilian news website of a video filmed last December 17 by Pedrinhas prisoners of the decapitated and tortured bodies of rival inmates inside the jail has highlighted some of the problems present in the country's prison system which houses nearly twice as many prisoners as its capacity, according to official statistics. (Photo by Douglas Cunha/Reuters/O Estado do Maranhão)

Players perform during a game at the first Bubble Soccer tournament in Hitzkirch, near Lucerne, Switzerland, June 27, 2015. Bubble Soccer, also known as Zorb Soccer, is becoming increasingly popular around the world. The game is a recreation of playing soccer whilst encased in an inflated zorb which covers the players upper-body and head. (Photo by Urs Flueeler/EPA)