Syrian Internal Security Forces dance in celebration during their graduation ceremony, at Ain Issa desert base, in Raqqa province, northeast Syria, Thursday, July 20, 2017. Some 250 residents of Syria's Raqqa province are the latest batch to graduate from a brief U.S-training course that is preparing an internal security force to hold and secure areas as they are captured from Islamic State militants. (Photo by Hussein Malla/AP Photo)

Jackie Barajas of Chula Vista dressed as Loki at Comic-Con in San Diego, USA on July 22, 2017. (Photo by K.C. Alfred/San Diego Union-Tribune via ZUMA Press/Rex Features/Shutterstock)

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)

A remote-controlled plane in the form of a witch flies over a neighborhood as the sun sets during Halloween in Encinitas, California, U.S. October 31, 2016. (Photo by Mike Blake/Reuters)

CANADA: Stanley Ferdinand filets large trout he caught in Great Bear Lake in Deline, Northwest Territories, Canada September 8, 2016. (Photo by Pat Kane/Reuters)

Dakar Rally, 2017 Paraguay-Bolivia-Argentina Dakar rally, 39th Dakar Edition, First stage from Asuncion, Paraguay to Resistencia, Argentina on January 2, 2017. Adrien Metge of France pushes his Sherco. (Photo by Ricardo Moraes/Reuters)

Cambridge students the morning after the Trinity and Jesus college May Balls in Cambridge, United Kingdom on June 19, 2018. Students at Cambridge University celebrate the end of the academic year with the May Balls. (Photo by South West News Service)