Event curators Harry Parr (L) and Sam Bompas (R) sit in paddle boats in the Truvia Voyage of Discovery installation on the roof of Selfridges department shop on July 21, 2011 in London, England. Selfridges is opening its roof to the public for only the second time since WW2 to host the installation, which includes a boating lake with dyed water and bar. (Photo by Matthew Lloyd/Getty Images)

A view of the screen of a ZaZZZ vending machine that contains cannabis flower, hemp-oil energy drinks, and other merchandise at Seattle Caregivers, a medical marijuana dispensary, in Seattle, Washington February 3, 2015. Vending machines selling medical marijuana opened for business in Seattle on Tuesday, in what the company providing them billed as a first-in-the-state innovation that it expects to expand to other cities and states where pot is legal as medicine. (Photo by David Ryder/Reuters)

Dancers perform during the Opening Ceremony of the Rio 2016 Olympic Games at Maracana Stadium on August 5, 2016 in Rio de Janeiro, Brazil. (Photo by Jamie Squire/Getty Images)

Bradley Hemmings and Jenny Sealey MBE pose for the camera with a Giant Iron Man on the set of Iron Man at the Greenwich and Docklands Festival in St Alfege Park on June 24, 2011 in London, England after they are announced by LOCOG as the Artistic Directors for the Paralympic Games Opening Ceremony. (Photo by Christopher Lee/Getty Images)

Jensen a two-year-old False Map turtle, from the Mississippi River, gets used to his new home at Blackpool Sea Life Centre on February 13, 2012 in Blackpool, England. (Photo by Christopher Furlong/Getty Images)

2016 Rio Olympics, Opening ceremony, Maracana, Rio de Janeiro, Brazil on August 5, 2016. Athletes of Colombia take part in the opening ceremony. (Photo by Kai Pfaffenbach/Reuters)

The first gender-neutral restroom in the Los Angeles school district is seen at Santee Education Complex high school in Los Angeles, California, U.S., April 18, 2016. (Photo by Lucy Nicholson/Reuters)

A woman walks past a painting by Jenny Saville entitled “Red Stare Head IV” on display in the Royal Academy of Arts' Summer Exhibition on June 2, 2011 in London, England. The Summer Exhibition is the world's largest open submission contemporary art show, now in its 243rd year, with over 12,000 entries received from 27 countries. The exhibition features over 1100 works of art including: painting, sculpture, photography, architecture and film, it officially opens to the public on June 7, 2011. (Photo by Oli Scarff/Getty Images)