A man wearing a water-filled helmet in which a goldfish swims performs an act titled “Aquaman” during the Night Festival 2016 in Singapore, 20 August 2016. The ninth edition of the festival will run from 19 to 27 August and features installations and performances by a range of international and local artists. (Photo by Wallace Woon/EPA)

North Korean military participate in the celebration of the 70th anniversary of the founding of the ruling Workers' Party of Korea, in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on early October 11, 2015. (Photo by Reuters/KCNA)

Singer Rihanna prepares for a photoshoot with photographer Annie Leibovitz in Havana, Cuba, May 28, 2015. (Photo by Reuters/Stringer)

An Afghan teacher, in brown, helps school children run from the site of clashes near the Pakistan consulate in Jalalabad, capital of Nangarhar province, Afghanistan, Wednesday, January 13, 2016. Several members of the Afghan security forces were killed Wednesday after unidentified gunmen attacked the Pakistani consulate in a volatile eastern province, an official said on Wednesday. (Photo by Mohammad Anwar Danishyar/AP Photos)

Participants take part in the annual Great Spitalfields Pancake Race in aid of London's Air Ambulance in London, Britain February 9, 2016. (Photo by Stefan Wermuth/Reuters)

Russia's Ekaterina Birlova casts a shadow on the sand as she serves to Poland during a women's beach volleyball match at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Tuesday, August 9, 2016. (Photo by Marcio Jose Sanchez/AP Photo)

A bishop walks past a new street-art collage by Italian artist Maupal showing Pope Francis playing tic-tac-toe and drawing peace signs as a Swiss guard keep watches the street near the Vatican on October 19, 2016 in Rome. (Photo by Tiziana Fabi/AFP Photo)

Traffic police stand at the side of a road in Pyongyang on November 25, 2016. (Photo by Ed Jones/AFP Photo)