Russian communists lay flowers at Soviet leader Joseph Stalin's tomb on Red Square next to the Kremlin wall in Moscow, Russia, December 21, 2015. Russian communists are marking the 136th anniversary of Josef Stalin's birthday. (Photo by Sergei Ilnitsky/EPA)

In this photo taken late Thursday, May 7, 2015, a prison guard, left, and seated inmates cast shadows on a wall while waiting for the beginning of a rock concert by Romanian band Pro Musica, inside the Popa Sapca jail in Timisoara, western Romania. (Photo by Adi Piclisan/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)

Protest posters are attached to the walls surrounding the “Occupy London” camp outside St. Paul's Cathedral on November 01, 2011 in London, England. The Dean of St. Pauls Cathedral The Very Reverend Graeme Knowles resigned yesterday over the church's handling of the anti-capitalist “Occupy London” demonstration, which continues to occupy the grounds outside the cathedral. (Photo by Dan Kitwood/Getty Images)

A doorman stands at the entrance of the “The Walled Off Hotel” in the West Bank city of Bethlehem, Friday, March 3, 2017. The owner of a guest house packed with the elusive artist Banksy's work has opened the doors of his West Bank establishments to media, showcasing its unique “worst view in the world”. The hotel, several of whose rooms look onto an Israeli security watchtower, is awash in the trademark satirical work of the mysterious artist. (Photo by Dusan Vranic/AP Photo)

Buildings in Nogales, Mexico (R) are separated by a border fence from Nogales, Arizona, United Sates, October 9, 2016. Building a wall along the U.S.- Mexico border has been a contentious subject in this year's U.S. presidential election. In parts of California and Arizona, a wall already exists. It runs across rocky deserts, flowing sand dunes and miles of agricultural land. (Photo by Mike Blake/Reuters)

A man inspects a plastic cover placed over an artwork attributed to Banksy on May 17, 2012 in London, England. The stencilled image depicts a poor child making Union Jack flags on a sewing machine and is located on the wall of a Poundland discount shop in the Wood Green area of north London. (Photo by Peter Macdiarmid)

The walls of Sydney's Town Hall Station are bedecked to resemble a Woolworths' supermarket shelf in Australia's first virtual supermarket, at Town Hall Station on February 19, 2012 in Sydney, Australia. (Photo by Marianna Massey/Getty Images for Woolworths)