Joe Deedon, president of TAC ONE Consulting, demonstrates searching for a shooter in a middle school during an Active Shooter Response course offered by TAC ONE in Denver April 2, 2016. According to TAC ONE, the course, which is offered for the first time to concealed weapons permit carrying civilians, is designed at preparing people to effectively save lives prior to the arrival of law enforcement at an active shooter incident. (Photo by Rick Wilking/Reuters)

Model friends Bella Hadid, Kendall Jenner, Stella Maxwell and actress Kristen Stewart and are seen having dinner together in Milan, Italy on June 16, 2018. Bella and Kendall cheekily showed the camera middle finger while couple Stella and Kristen talked. (Photo by Splash News and Pictures)

A guest dressed as a zombie attends the Middle East Film & Comic Con (MEFCC) in Gulf emirate of Dubai, United Arab Emirates, 11 April 2019. The event runs until 13 April 2019. (Photo by Ali Haider/EPA/EFE)

A Chinese shopper sleeps on a bed in the showroom of the IKEA store on July 6, 2014 in Beijing, China. Of the world's ten biggest Ikea stores, 8 of them are in China to cater to the country's growing middle class. The stores are designed with extra room displays given the tendency for customers to make a visit an all-day affair. Store management does not discourage shoppers from sleeping on Ikea furniture, even marking them with signs inviting customers to try them out. (Photo by Kevin Frayer/Getty Images)

A demonstrator with face painted in the colours of the Palestinian flag protests outside the Israeli Embassy in west London July 26, 2014. Foreign ministers from the United States, Europe and the Middle East called on Saturday for an extension of the 12-hour ceasefire between Israel and Hamas in the Gaza Strip, French Foreign Minister Laurent Fabius said. (Photo by Luke MacGregor/Reuters)

A colourful morning sunrise on Christmas Eve at Victoria Tower on Castle Hill, West Yorkshire, England on December 24, 2017. The history of human activity on the Castle Hill goes back over 4000 years. The site was developed as an iron age hill fort, surrounded by defensive ditches and ramparts. In the Middle Ages there was a castle on the hill, of which the well remains. The present tower was built to commemorate Queen Victoria's Diamond Jubilee of 1897. (Photo by Charlotte Graham/ZUMA Wire/Rex Features/Shutterstock)

A combination photo shows various popular street foods under $6 from various hawker food stalls and eateries in Singapore, taken between July 28 to 31, 2016. Top row (L to R) bak chor mee, soya sauce chicken; Middle row (L to R) laksa, hokkien mee, nasi lemak, ice kachang; Bottom row (L to R) rojak, roti prata and satay. (Photo by Edgar Su/Reuters)

In this Wednesday, April 15, 2020 file photo, a motorcycle delivery man rides past a billboard urging people to stay home over the coronavirus pandemic in Dubai, United Arab Emirates. Wealthier Western countries are considering how to ease lockdown restrictions and start taking gradual steps toward reviving business and daily life. But many developing countries, particularly in the Middle East and Africa, can hardly afford the luxury of any misstep. (Photo by Jon Gambrell/AP Photo/File)