Employees work at a sorting centre of Zhongtong (ZTO) Express ahead of the Singles Day shopping festival, Chaoyang District, Beijing, November 8, 2015. On China's giant Singles Day internet shopping festival, the country's delivery firms are stretched so thin that they are looking for tie-ups, listings and new investors to husband their resources. (Photo by Jason Lee/Reuters)

An elephant “kisses” a visitor during a show at an elephant training school in Xishuangbanna, Yunnan province, April 18, 2015. Some 16 elephants live at the school and give four 30-minute performances everyday for visitors. (Photo by Wong Campion/Reuters)

A Naga sadhu, or naked Hindu holy man, performs a ritual inside his tent during Kumbh Mela, or Pitcher festival, at Trimbakeshwar, India, Friday, August 28, 2015. Hindus believe taking a dip in the waters of a holy river during the festival will cleanse them of their sins. The festival is held four times every 12 years. (Photo by Rajanish Kakade/AP Photo)

US model Binx Walton strutted out with a boob exposed and only a glittery love heart ­protecting her modesty in Anthony Vaccarello’s debut show for Saint ­Laurent on September 27, 2016. The Sun found out how the trend measured up on trip to the shops. Here: Isabella Besque 21 from London tries out the nipple cover look as seen Paris Fashion week on the streets of London, England on October 7, 2016. (Photo by Stewart Williams/The Sun)

A girl plays on a pile of discarded flowers outside a market, the day after the Diwali celebrations in Mumbai, India October 31, 2016. (Photo by Shailesh Andrade/Reuters)

People walk past the Sleepwalker, a sculpture along the High Line in New York, US on May 10, 2016. The hyperrealistic work by Brooklyn artist Tony Matelli is part of the linear park’s Wanderlust exhibition. (Photo by Xinhua/Barcroft Images)

Riot police stand guard behind a fire as refinery workers hold a blockade of the oil depot of Douchy-Les-Mines to protest against the government's proposed labour reforms, on May 25, 2016. Refinery workers stepped up strikes that threaten to paralyse France weeks ahead of the Euro 2016 tournament as the government moved to break their blockades, escalating a three-month tug-of-war over labour reforms. (Photo by François L.O./AFP Photo)

Contorsionist Rich Miteku performs during the opening of the 41st Monte-Carlo International Circus Festival in Monaco on January 19, 2017. (Photo by Valery Hache/AFP Photo)