A driverless vehicle runs at Vanke's Building Research Centre testing area in Dongguan, south China's Guangdong province November 2, 2015. The country's largest property developer, China Vanke, is investing in its own robots to do certain jobs in the face of a labor shortage in the world's most populated country. This driverless car is among the robots that Vanke is aiming to bring in. (Photo by Tyrone Siu/Reuters)

In this photo taken June 3, 2009, a female North Korean soldier looks out from behind a barbed-wire fence around a camp on the North Korean river banks across from Hekou, northeastern China's Liaoning province. North Korea's top court has convicted two U.S. journalists, and sentenced them to 12 years in labor prison, the country's state news agency reported Monday. (Photo by Ng Han Guan/AP Photo)

A laborer works at an upside-down house under construction at Fengjing Ancient Town, Jinshan District, south of Shanghai, March 17, 2014. Workers are putting the final touches on this eccentric tourist attraction built at the “China Folk Painting Village”. Furniture will also be placed upside down in the house, which is expected to open the public in April, according to local media. (Photo by Carlos Barria/Reuters)

A tour group wanders through block 7 of Eastern State Penitentiary in Philadelphia, Pennsylvania April 30, 2014. Opened in 1829, with the original corrective system of “confinement in solitude with labor”, the penitentiary housed about 75,000 inmates in its 142 years of operation. At Eastern State reunions, former inmates, staff and guard gather to share memories and trade stories and get a chance to describe their experiences in question-and-answer sessions with the public. (Photo by Mark Makela/Reuters)

An Afghan laborer works at a brick kiln, in Jalalabad, Afghanistan, 24 February 2020. Afghan President Ghani said on 21 February, said that a seven-day reduction in violence promised by the Taliban will determine the government's next steps in Afghanistan's peace process. The Taliban has announced a decrease in hostilities in an agreement with the United States as a preliminary step to signing a peace deal with Washington on 29 February. (Photo by Ghulamullah Habibi/EPA/EFE)

Tourists wearing protective face masks walk in Nanluoguxiang alley, a famous touristic spot at Hutong neighborhood, in Beijing, China, 01 May 2020. China is loosening up nationwide restrictions after months of lockdown over the coronavirus crisis. Labor Day in the country kicked off with a long weekend and an extended holiday, from 01 to 05 May, after the tourism industry has been hit during the coronavirus and COVID-19 disease pandemic. (Photo by Roman Pilipey/EPA/EFE)

An officer is on fire as demonstrators clash with police during a protest against plans for new austerity measures on June 28, 2011 in Athens, Greece. Greece's largest labor unions have called for a 48-hour strike, while the Socialist government is beginning to push through legislation for cost cutting reforms. (Photo by Milos Bicanski/Getty Images)