An opposition activist clashes with the police during a march against Venezuelan President Nicolas Maduro held on May Day, in Caracas on May 1, 2017. Security forces in riot vans blocked off central Caracas Monday as Venezuela braced for pro- and anti- government May Day protests one month after a wave of deadly political unrest erupted. (Photo by Federico Parra/AFP Photo)

An AH-64D Apache attack helicopter flies in front of a wall of fire during the South Carolina National Guard Air and Ground Expo at McEntire Joint National Guard Base, South Carolina, U.S. on May 6, 2017. (Photo by Jorge Intriago/Reuters/Courtesy Air National Guard)

People enjoying the races on a wet day at Chester Racecourse on May 12, 2017 in Chester, England. (Photo by Alan Crowhurst/Getty Images)

An Iraqi military vehicle passes displaced Iraqi boys returning to their homes in West Mosul's Oreibi neighbourhood after government forces retook control of the area from the Islamic State (IS) group during the ongoing offensive against the jihadists on May 21, 2017. (Photo by Ahmad Al-Rubaye/AFP Photo)

Russian woman takes selfie near military vehicle during the rehearsal for a military parade in Moscow, Russia, 29 April 2019. Russia will hold a Victory Day military parade on 09 May 2019 to mark the 74th anniversary since the capitulation of Nazi Germany in 1945. (Photo by Yuri Kochetkov/EPA/EFE)

Models perform during a Muslim fashion show an airport train in Jakarta, Indonesia on Thursday, May 2, 2019. The fashion show was held to great to upcoming fasting month of Ramadan, the holiest month in Muslim calendar. (Photo by Tatan Syuflana/AP Photo)

Garrison Ireland Leigon member John O'Dwyer dressed as the character Darth Vader looks out towards Skellig Michael island on May 4, 2019 in Portmagee, Ireland. The latest Star Wars movies such as The Last Jedi have featured the famous Skellig Michael islands situated off the coast of the small Irish fishing village. The May the Fourth Star Wars festival is taking place in the small County Kerry village for the second year running as millions of fans worldwide celebrate the science fiction series. The quiet costal setting has seen a sharp rise in the number of tourists and fans visiting the area. (Photo by Charles McQuillan/Getty Images)

A Sotheby's employee poses with a claw-set diamond ring weighing 36.57 carats during a press preview of an upcoming auction from Sotheby's in Geneva, Switzerland, 08 May 2019. The ring is expected to reach between 4,500,000 to 5,500,000 US Dollars during the “Magnificent Jewels and Noble Jewels” auction on May 14 in Geneva. (Photo by Valentin Flauraud/EPA/EFE)