Mahouts and their elephants display a poster during a campaign ahead of the August 7 referendum in Auytthaya province, north of Bangkok, Thailand, August 1, 2016. Officials across the country are drumming up campaigns to encourage voting on the draft constitution in a referendum on Sunday. (Photo by Chaiwat Subprasom/Reuters)

People walk on a sightseeing platform in Zhangjiajie, Hunan Province, China, August 1, 2016. China has opened a 100-metre-long glass skywalk stretching around a cliff on the side of the Tianmen Mountain. The skywalk provides a view of a 300-metre drop and overlooks Tongtian Avenue, a mountain road with 99 turns that snakes up the mountain. When translated in English, it means “Avenue to the Sky”. (Photo by Reuters/Stringer)

A combination of pictures shows people taking photos of themselves in Tiananmen Square as they celebrate National Day marking the 67th anniversary of the founding of the People's Republic of China, in Beijing October 1, 2016. (Photo by Damir Sagolj/Reuters)

A voodoo believer, dressed as "Gede", a spirit of voodoo, sits on the cross of Baron Samdi during celebrations at the cemetery of Port-au-Prince, Haiti, November 1, 2016. Voodoo believers and devotees offer candles, alcohol and food. The Day of the Dead is celebrated on the first two days of November during All Saints and All Souls Day. (Photo by Andres Martinez Casares/Reuters)

People take part in a Halloween street party at Lan Kwai Fong on October 31, 2016 in Hong Kong. Halloween, a contraction of All Hallows' Evening, falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Lam Yik Fei/Getty Images)

Members of the Oath Keepers and general public return fire during a simulated attack as they take part in a tactical training session in northern Idaho, U.S. October 1, 2016. In April 2015 Reuters photographer Jim Urquhart was assigned to cover the Oath Keepers during a tour of the Sugar Pine gold mine in Oregon after the group of former cops, military, firefighters and other first responders had risen to prominence during a standoff in Nevada over land rights. (Photo by Jim Urquhart/Reuters)

A surfer rides a large wave at El Bocal during the Vaca Gigante (Big Cow) giant wave surf competition in Santander, northern Spain December 17, 2016. (Photo by Vincent West/Reuters)

A competitor laughs while taking part in the office chair race ISU-1 Grand Prix in Tainan, southern Taiwan April 24, 2016. It was the first time such a race was held in Tainan, as part of the “ISU-1 GP” (Grand Prix) that began in Japan in 2010, according to businesses on Jhengsing Street and Haian Road in the city's West Central District and the city's Tourism Bureau, which organized the event. The fastest rider only took six seconds to complete the 30-meter race. (Photo by Tyrone Siu/Reuters)