Challenger Bulgarian heavyweight boxer Kubrat Pulev (R) lies in the ring after being knocked down by Ukrainian WBA, WBO, IBO and IBF heavyweight boxing world champion Vladimir Klitschko (L), who celebrates with his brother Vitali (2nd L), as referee Tony Weeks checks on him after their title fight in Hamburg, November 15, 2014. World heavyweight champion Vladimir Klitschko knocked out Bulgarian challenger Kubrat Pulev with a fierce left hook in the fifth round on Saturday to retain his IBF title and end his opponent's unbeaten record. (Photo by Fabian Bimmer/Reuters)

(Top L-R) Playboy Playmates Anna Sophia Berglund, Kayla Rae Reid, Dominique Jane, Heather Rae Young, Alexandra Tyler, Val Keil, (bottom L-R) Audrey Aleen Allen, Ashley Doris, Hiromi Oshima, and Shanice Jordyn attend the Playboy Midsummer Night's Dream party at the Marquee Nightclub at The Cosmopolitan of Las Vegas on August 27, 2016 in Las Vegas, Nevada. (Photo by David Becker/Getty Images for Playboy Enterprises)

Winti spiritual leader Ramon Mac-Nack (2nd L) looks on as as his bride Melissa Karwafodi (2nd R) hands a gourd to a Maroon priest (L) as they are wedded in the first Winti marriage ever to be held in public, in district Para, Suriname, November 16, 2015. The Winti religion, which formed centuries ago out of elements of different religious traditions that African slaves brought with them to Suriname, was considered a form idolatry and prohibited by law since the days of slavery until it was finally officially recognized in 1971. (Photo by Ranu Abhelakh/Reuters)

US President Donald Trump' s daughter and senior White House adviser Ivanka Trump (2nd R) poses for a photo on a balcony of the VIP tent at the Olympic sliding centre with US army luge athletes Taylor Morris (L) and Matt Mortensen (2nd L), and US women’s bobsleigh silver medallist Lauren Gibbs (R) before the ski jump tower at the men' s four- man bobsleigh event of the Pyeongchang Winter Olympic games in Pyeongchang on February 25, 2018. (Photo by Eric Gaillard/Reuters)

Robot couple Xiaolan (L) and Xiaotao carry trays of food at a restaurant in Jinhua, Zhejiang province, China, May 18, 2015. The restaurant, which opened on Monday, has two robots delivering food for customers. The robots were designed as a couple, Xiaolan and Xiaotao, according to local media. (Photo by Reuters/Stringer)

Dancers from the School of American Ballet Chloe Ellis (R) and Amarra Hong (L) prepare for a performance at the Queens Theatre in the Queens borough of New York February 28, 2016. (Photo by Shannon Stapleton/Reuters)

Dustin Murley (L) and Jessey Sisson race on their ostriches during the annual Ostrich Festival in Chandler, Arizona March 10, 2013. (Photo by Joshua Lott/Reuters)

Team McLaren Mercedes drivers Lewis Hamilton (L) and Jenson Button unveil the new MP-27 Formula 1 car at the McLaren technology centre on February 1, 2012 in Woking, England. (Photo by Mark Thompson/Getty Images)