A fighter of Libyan forces allied with the U.N.-backed government runs for cover during a battle with Islamic State fighters in Sirte, Libya, July 31, 2016. (Photo by Goran Tomasevic/Reuters)

Participants re-enact the “Battle of Five Armies” from J.R.R. Tolkien's novel “The Hobbit” in a forest near the town of Doksy, Czech Republic June 6, 2015. According to event organizers, hundreds of enthusiasts dressed as characters such as elves, dwarves, goblins and orcs from the book “The Hobbit” re-enacted the clash. (Photo by David W. Cerny/Reuters)

A Baby sumatran orangutan (Pongo abelii) plays around in a tree as they train at Sumatran Orangutan Conservation Programme's rehabilitation center on November 12, 2016 in Kuta Mbelin, North Sumatra, Indonesia. The Orangutans in Indonesia have been known to be on the verge of extinction as a result of deforestation and poaching. Found mostly in South-East Asia, where they live on the islands of Sumatra and Borneo, the endangered species continue to lose their habitat as a result of corporate expansion in a developing economy. Indonesia approved palm oil concessions on nearly 15 million acres of peatlands over the past years and thousands of square miles have been cleared for plantations, including the lowland areas that are the prime habitat for orangutans. (Photo by Ulet Ifansasti/Getty Images)

Iraqi forces launch a rocket in Mosul's eastern Al-Intisar neighbourhood on December 30, 2016, during an ongoing military operation against Islamic State (IS) group jihadists. Iraqi forces advanced on December 29 after declaring a new phase in their offensive on eastern Mosul, stepping up efforts to reclaim the Islamic State group's last major stronghold in the country. (Photo by Ahmad Al-Rubaye/AFP Photo)

A view of the screen of a ZaZZZ vending machine that contains cannabis flower, hemp-oil energy drinks, and other merchandise at Seattle Caregivers, a medical marijuana dispensary, in Seattle, Washington February 3, 2015. Vending machines selling medical marijuana opened for business in Seattle on Tuesday, in what the company providing them billed as a first-in-the-state innovation that it expects to expand to other cities and states where pot is legal as medicine. (Photo by David Ryder/Reuters)

Members of the 1st Tennessee wait to take part in in a demonstration of a battle during ongoing activities commemorating the 150th anniversary of the Battle of Gettysburg, Friday, June 28, 2013, at at Bushey Farm in Gettysburg, Pa. Union forces turned away a Confederate advance in the pivotal battle of the Civil War fought July 1-3, 1863, which was also the war's bloodiest conflict with more than 51,000 casualties. (Photo by Matt Rourke/AP Photo)

Residents observe a police officer take up position during an operation at the Mare slums complex in Rio de Janeiro March 25, 2014. The federal troops have taken control of security operations in Mare slums complex to help quell a surge in violent crime following attacks by drug traffickers on police posts in three slums on the north side of the city, government officials said. (Photo by Ricardo Moraes/Reuters)

A man dresses as a plague doctor at the Bannockburn Live event on June 28, 2014 in Stirling, Scotland. The 700th anniversary of the historic battle that saw the outnumbered Scots conquer the English led by Edward II in the First War of Scottish Independence. (Photo by Peter Macdiarmid/Getty Images)