A demonstrator is detained by police officers during a protest in Hong Kong, China on August 31, 2019. Hong Kong police fired tear gas and water cannons and pro-democracy protesters threw petrol bombs in the latest in a series of chaotic clashes that have plunged the Chinese-ruled city into its worst political crisis in decades. (Photo by Kai Pfaffenbach/Reuters)

A pro-democracy demonstrator fights with a Soviet soldier on top of a tank parked in front of the Russian Federation building on August 19, 1991, after a coup toppled Soviet President Mikhail Gorbachev. The same day, thousands in Moscow, Leningrad, and other cities answered Russian Republic President Boris Yeltsin's call to raise barricades against tanks and troops. (Dima Tanin/AFP/Getty Images)

A Kashmiri girl holds her brother in the doorway of their home while watching protesters shout pro-freedom and anti-Indian slogans during mourning and protests held in downtown Srinagar on August 22, 2016, following the killing of teenager Irfan Ahmed by security forces. Teenager Irfan Ahmed was killed after he was hit in the chest by a teargas canister fired by Indian security forces to quell pro-freedom protests in the Kashmiri capital on August 21. More than 60 civilians have been killed in clashes between protesters and security forces, and thousands more injured in the worst violence to hit the Himalayan region since 201. Indian-administered Kashmir has been in the grip of almost daily anti-India protests and rolling curfews sparked by the killing on July 8 of a popular rebel leader, Burhan Wani, in a gunfight with government forces. (Photo by Tauseef Mustafa/AFP Photo)

Russian President Vladimir Putin (R) looks through a window of a research bathyscaphe while submerging into the waters of the Black Sea as he takes part in an expedition near Sevastopol, Crimea, August 18, 2015. (Photo by Alexei Nikolsky/Reuters/RIA Novosti/Kremlin)

Marie Lou looks out of the window of gypsy folklore wagon on May 24, 2016 in Staintes Maries de la Mere near Arles, France. Gypsies from all over Europe worship “Sara the Black”, their Saint and patroness, for one week. Sara's statue is situated in the crypt of the church. She wears a multicoloured dress and will carried by the gypsies to the sea at this afternoon. (Photo by Thomas Lohnes/Getty Images)

A girl looks out from the window of a “La Sabana” tourist train in La Caro March 1, 2015. The “La Sabana” tourist train that runs through the capital was founded by Eduardo Rodriguez, a railway engineer. Rodriguez has worked on Colombia's railway system his whole life and now, with an air of nostalgia, transports thousands of tourists in renovated steam locomotives that he fixes in Bogota's Central Station which dates back to 1913. (Photo by Jose Miguel Gomez/Reuters)

Juan Carlos Vilchez, 18-months-old, dressed to represent horror movie icon Chucky, looks into a storefront mall window, in Managua, Nicaragua, Friday, October 31, 2014. Juan Carlos is wearing a first place winner that he won earlier, for best Halloween costume in his age group. (Photo by Esteban Felix/AP Photo)

Romanian military doctors and medical students sit on a bus behind steamy windows before the National Day parade in Bucharest, Romania, Thursday, December 1, 2016. Military planes and helicopters flew over the Romanian capital Thursday as thousands turned out to celebrate the national day, marking the date when the country reunified with Transylvania in 1918. (Photo by Vadim Ghirda/AP Photo)