A runner competes in the Great Wall Marathon at the Huangyaguan Great Wall outside Beijing, China, May 18, 2019. (Photo by Thomas Peter/Reuters)

Union Berlin players celebrate after the Bundesliga playoff second leg match between 1. FC Union Berlin and VfB Stuttgart at Stadion an der alten Foersterei on May 27, 2019 in Berlin, Germany. (Photo by Annegret Hilse/Reuters)

Ratana Das, 40, a female vendor, carries sacks full of clothes at a second-hand clothing market early morning in Kolkata, India, March 10, 2016. Das said she was born and brought up in Kolkata and feels proud being a resident of the city that gives her he opportunity to be financially independent. (Photo by Rupak De Chowdhuri/Reuters)

Syrian Internal Security Forces dance in celebration during their graduation ceremony, at Ain Issa desert base, in Raqqa province, northeast Syria, Thursday, July 20, 2017. Some 250 residents of Syria's Raqqa province are the latest batch to graduate from a brief U.S-training course that is preparing an internal security force to hold and secure areas as they are captured from Islamic State militants. (Photo by Hussein Malla/AP Photo)

The Jet Propulsion Lab team's RoboSimian robot turns on a valve at a simulated disaster-response course during day one of the Defense Advanced Research Projects Agency (DARPA) Robotics Challenge finals in Pomona, California, June 5, 2015. (Photo by David McNew/Reuters)

Former Playboy Bunny Angie Best prepares backstage ahead of her return as the iconic Bunny Mother exclusively at the Telling Tales event at Playboy Club London on September 21, 2017 in London, England. (Photo by Tim P. Whitby/Tim P. Whitby/Getty Images for Playboy)

Svetlana Tseyko feeds a 10-month-old moose named Grisha in the courtyard in the village of Abramy, some 160 km northwest of Minsk, on February 21, 2017. (Photo by Sergei Gapon/AFP Photo)

(L-R) Playmate Victoria Silvstedt, Donald Trump and Melania Knauss at the Playboy 50th Anniversary celebration December 4, 2003 in New York City. (Photo by Peter Kramer/Getty Images)