A member of the Air Force's Wings of Blue Parachute Demonstration Team salutes as he jumps out of an aircraft, during the opening ceremony of Aviation Nation 2017 Nellis Air and Space Expo at Nellis Air Force Base, Nev., November 10, 2017. (Photo by Senior Airman Kevin Tanenbaum/Reuters/U.S. Air Force)

People perform during celebrations to commemorate the 70th anniversary of the establishment of the Vietnam Public Security police force at the National Convention Center in Hanoi August 18, 2015. The Vietnam Police force was founded on August 19, 1945, the day of the anti-colonial people's uprising known as the August Revolution. (Photo by Reuters/Kham)

Two Corgi dogs collide as they cross the finish line during the SoCal “Corgi Nationals” championship at the Santa Anita Horse Racetrack in Arcadia, California on May 27, 2018. The event saw hundreds of Corgi dogs compete for the fastest dog title at the 17 race event. (Photo by Mark Ralston/AFP Photo)

In this Thursday, October 18, 2018 photo, contestants wait for their performance backstage during the National Amateur Body Builders' Association competition in Tel Aviv, Israel. Dozens of glistening competitors took the stage for the annual body building and fitness competition last week. But behind the scenes, machismo makes way for cooperation. (Photo by Oded Balilty/AP Photo)

A National Bolivarian Police officer rescues a man who was being attacked by protesters, who then threw rocks at them, during a protest demanding food a few blocks from Miraflores presidential palace in Caracas, Venezuela, Thursday, June 2, 2016. Venezuela is seeing rising frustration with widespread food shortages and triple-digit inflation. (Photo by Fernando Llano/AP Photo)

A tourist stands at an edge of the singing sand, the 150-metre-high by three-kilometre-long dune that generates a low-pitched, organ-like rumble in dry weather, in Altyn-Emel national park in Almaty region, Kazakhstan, May 12, 2016. (Photo by Shamil Zhumatov/Reuters)

A paper mache pig meant to mock Donald Trump sits on display at a protest against the Republican presidential candidate before the start of the Republican National Convention in Cleveland, Ohio, USA, 17 July 2016. Numerous protest groups are expected in Cleveland throughout the four-day-long convention. (Photo by Jim Lo Scalzo/EPA)

Kevin Kvasnicka (L) and Jesse Gonzales openly carry firearms as they watch U.S. Republican presidential nominee Donald Trump speak on a big screen television along East 4th street during the Republican National Convention in Cleveland, Ohio, U.S., July 21, 2016. (Photo by Adrees Latif/Reuters)