Cheng Chen (R), a 27-year-old worker at a state-owned enterprise, poses for a photograph with his nephew who is wearing his home-made Iron Man armour, in Xuzhou, Jiangsu province April 13, 2015. It cost Cheng about 500 yuan ($81 USD) to make the armour, which weighs about 4 kilograms, with plastic boards and LED lights, local media reported. (Photo by Reuters/Stringer)

Carrying a portable shrine on their shoulders, participants all clad in traditional happi coats, parade through precincts of the Kanda Myojin shrine during the annual summer festival in Tokyo, Saturday, May 9, 2015. (Photo by Eugene Hoshiko/AP Photo)

A traffic police woman whistles at a pedestrian, Monday, July 27, 2015, in Pyongyang, North Korea where its citizens are having a one-day national holiday to celebrate the country's 62nd anniversary of the armistice that ended the Korean War. (Photo by Wong Maye-E/AP Photo)

Mrs. Marie Graskamp of Milwaukee shows the different positions one might assume when entering the bomb shelter in Milwaukee September 3, 1958. This circular entrance is about three feet in diameter. This is the entrance (according to the builders) that would connect to the cellar of a home assuming the shelter was in the ground for added protection. If a bombing should occur, all members of family would proceed to the cellar and then through the circular port into the shelter. (Photo by AP Photo)

Trees are reflected on the surface of a lake in the Okefenokee swamp lands in Georgia, USA on October 21, 2017. (Photo by Chris Moore/Solent News & Photo Agency)

Rockhopper penguins live up to their name as they navigate the rugged coastline of Marion Island in the southern Indian Ocean. (Photo by Thomas P. Peschak)

Pakistani street performers sit around fire waiting for customers on a chilly evening in Rawalpindi, Pakistan, Wednesday, February 10, 2016. (Photo by B.K. Bangash/AP Photo)

A woman with high heels walks on a sidewalk which is renovated on August 10, 2017 in downtown Moscow, as the city continues with preparations for next year's FIFA World Cup. (Photo by Mladen Antonov/AFP Photo)