In this photograph taken on April 1, 2015, an Indonesian resident and child walk away from an abandoned school building as Mount Sinabung erupts in Karo district on the Indonesian island of Sumatra. According to authorities about 3,500 people were displaced after the February 2014 eruption of Mount Sinabung volcano and many are still living in evacuation centers as the volcano remains active. (Photo by Sutanta Aditya/AFP Photo)

Yang Juan, an employee at Goopal Group, takes a nap in her seat after lunch, in Beijing, China, April 21, 2016. Office workers sleeping on the job is a common sight in China, where a surplus of cheap labour can lead to downtime at work. But in China's technology sector, where business is growing faster than many start-up firms can hire new staff, workers burn the midnight oil to meet deadlines and compete with their rivals. Some companies provide sleeping areas and beds for workers to rest during late nights. (Photo by Jason Lee/Reuters)

Kenyan riot police officers raise batons over a man during a demonstration of Kenya's opposition supporters in Nairobi, on May 16, 2016. Opposition protestors led by former Prime Minister Raila Odinga gathered outside the Indepedent Electoral and Boundaries Comission building to demand the dismissal of IEBC commissioners, after alleged bias towards the ruling Jubillee Alliance Party. (Photo by Carl De Souza/AFP Photo)

Passengers embrace each other at the entrance to Istanbul's Ataturk airport, early Wednesday, June 29, 2016 following their evacuation after a blast. Suspected Islamic State group extremists have hit the international terminal of Istanbul's Ataturk airport, killing dozens of people and wounding many others, Turkish officials said Tuesday. (Photo by Emrah Gurel/AP Photo)

In this October 21, 2015, file photo, a young man rides a hoverboard along a Manhattan street toward the Empire State Building in New York. More than 500,000 hoverboards are being recalled after reports that they can burst into flames. The Consumer Product Safety Commission said Wednesday, July 6, 2016, it has received 99 reports of battery packs in the two-wheel motorized scooters catching fire or exploding that causing burns or property damage. The recalled hoverboards were made by eight companies. (Photo by Kathy Willens/AP Photo)

A handout picture provided by the press service of MORTON Group of Companies, show the balloon of Russian adventurer Fedor Konyukhov in the sky during his solo round-the-world balloon flight just after taking off from a spot near Northam, 96 kilometres north-east of Perth in Western Australia, 12 July 2016. Fedor Konyukhov took off from Northam on 12 July 2016 in attempt to beat the record of 13 days of American aviator Steve Fossett. (Photo by EPA/Morton Press Service)

A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

Chinese artist Zhou Jie takes a nap on an unfinished iron wire bed, one of her sculpture works, after lunch as a friend of hers looks on at Beijing Now Art Gallery, in Beijing August 11, 2014. Zhou started her art project titled “36 Days” on August 9, in which she would live inside an exhibition hall with an unfinished iron wire bed, some iron wire sculptures in the shape of stuffed animal dolls, a certain amount of food and her mobile phone, for 36 days. The entire process is open to visitors and she may also interact with them, according to Zhou. (Photo by Jason Lee/Reuters)