Visitors dressed in superhero costumes attend the Paris Comics Expo at the Parc Floral in Paris, France, April 15, 2016. (Photo by Charles Platiau/Reuters)

Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

Female North Korean traffic police officers gather in front of bronze statues of the late leaders Kim Il Sung and Kim Jong Il to pay their respects in Pyongyang, North Korea on Saturday, February 16, 2013. North Koreans turned out to commemorate what would have been the 71th birthday of Kim Jong Il who died on December 17, 2011. (Photo by David Guttenfelder/AP Photo)

A customer shops at an Alibaba rural service centre in Jinjia Village, Tonglu, Zhejiang province, China, July 20, 2015. E-commerce growth in the countryside now outpaces that in major cities, though fewer than one tenth of online purchases made on Alibaba platforms were shipped to rural areas in the first quarter of this year. Alibaba estimates the potential market at 460 billion yuan ($74 billion) by next year. (Photo by Aly Song/Reuters)

Restive woman driving. (Photo by Cultura Creative (RF)/Alamy Stock Photo)

Cat lounges and makes itself at home at the new Cat Café by Purina ONE on Wednesday, April 23, 2014 in New York. (Photo by Amy Sussman/Invision for Purina ONE/AP Images)

Blankets cover the bodies of a woman (right) and a man (left background) hit by a northbound Penn Central train (background) as they waited with a crowd at Pennsylvania Railroad station in Elizabeth, N.J. on June 8, 1968 to view the southbound train carrying the body of Sen. Robert F. Kennedy to Washington. The woman was identified as Mrs. Antoinette Severini, 54, and the man, John Curia (age unavailable), both of Elizabeth. (Photo by AP Photo)

A young Sandinista guerrilla takes aim with his 45 pistol as he stands waiting to do combat with the Nicaraguan National Guard in Managua June 23, 1979. The guerrillas still occupy major parts of the Capitol City. (Photo by McLendon/AP Photo)