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)

A man holds his umbrella during snowfall on the Areopagitou pedestrian street beneath the Acropolis hill during snowfall in Athens, Greece, January 10, 2017. (Photo by Alkis Konstantinidis/Reuters)

A painting of a Trabant car bursting through a wall in post unification Berlin, August 1993. (Photo by Steve Eason/Hulton Archive/Getty Images)

A silicon rug in the form of Adolph Hitler on display during an exhibition by Israeli artist Boaz Arad, at the Center for Contemporary Art February 22, 2007 in Tel Aviv, Israel. Arad is an Israeli artist who is dealing with the Holocaust in a provocative way. He uses the Holocaust to discuss human evil and contemporary Israel, which he says is torn and crumbling. (Photo by David Silverman/Getty Images)

A nurse consoles herself with a box of chocolates as she reads a paper-back thriller. (Photo by Hulton Archive/Getty Images). Circa 1955

Two dummy tanks being pushed along a road by German soldiers. (Photo by Hulton Archive/Getty Images). Circa 1925

King George V inspects the day's kill after a tiger hunt in India during his royal visit to celebrate his accession to the throne. (Photo by Hulton Archive/Getty Images). 1911

Grafitti by the illusive artist Banksy adorns the levee wall in the Lower Ninth Ward on August 29, 2008 in New Orleans, Louisiana. New works by the artist, whose paintings are also sold in galleries, have been popping up throughout New Orleans coinciding with the third anniversary of Hurricane Katrina. (Photo by Chris Graythen/Getty Images)