The Pink Floyd inflatable pig floats next to Broadcasting House to promote their new exhibition at the V&A museum, in London, Britain May 10, 2017. (Photo by Neil Hall/Reuters)

Justin Nelzen, in red vest, joins others as they work to rescue up to 70 horses along Cypresswood Drive near Humble along Cypress Creek, Monday, April 18, 2016, in Houston. More than a foot of rain fell Monday in parts of Houston, submerging scores of subdivisions and several major interstate highways, forcing the closure of schools and knocking out power to thousands of residents who were urged to shelter in place. (Photo by Mark Mulligan/Houston Chronicle via AP Photo)

Gas-masked men of the British Machine Gun Corps with a Vickers machine gun during the first battle of the Somme, 1916. (Photo by General Photographic Agency/Getty Images)

Couple getting intimate on couch. (Photo by Vincent Besnault/Getty Images)

In this photo taken on Friday, July 14, 2017, a student at a paramilitary camp for children calls the rank to attention outside Kiev, Ukraine. As the deadly conflict in eastern Ukraine entered its third year, some parents in Ukraine are anxious to make sure their children are ready to fight it, instead of swimming and playing volleyball. (Photo by Efrem Lukatsky/AP Photo)

Eleonora Brunacci and Mariano Di Vaio walk the red carpet ahead of the “Racer And The Jailbird (Le Fidele)” screening during the 74th Venice Film Festival at Sala Grande on September 8, 2017 in Venice, Italy. (Photo by Pascal Le Segretain/Getty Images)

A visitor tries out Lenovo augmented reality glasses with the Star Wars Jedi Challenges during the Mobile World Congress in Barcelona, Spain, February 26, 2018. The Mobile World Congress, the world' s biggest mobile fair, is held in Barcelona from February 26 to March 1. (Photo by Yves Herman/Reuters)

In this April 28, 2015 file photo, heads of tuna on a cart are carried by a fish dealer after the day's auction at Tsukiji Wholesale Market in Tokyo. In one of the biggest of Japan's many New Year holiday rituals, early on Tuesday, January 5, 2016, Tokyo's Tsukiji market will auction off with much fanfare a huge, glistening tuna, likely destined for one of the big sushi chains. If all goes as planned, it will be the last such auction at 80-year-old Tsukiji. (Photo by Shuji Kajiyama/AP Photo)