Couples take part in the “Love and Challenge Marathon” in Hanoi, Vietnam, 16 August 2015. Fifty couples, who are going to get married, participated in the event which is held the fifth time. This year, the winners of the marathon received a honeymoon trip to Malaysia. (Photo by Luong Thai Linh/EPA)

In this photo posted on Twitter, Sunday, May 3, 2015, and provided by NASA, Italian astronaut Samantha Cristoforetti sips espresso from a cup designed for use in zero-gravity, on the International Space Station. Cristoforetti, the first Italian woman in space, fired up the first espresso machine in space, which uses small capsules, or pods, of espresso coffee. (Photo by AP Photo/NASA)

An Indian Sikh devotee takes a dip in the holy sarover (water tank) at the Golden Temple on the eve of “Ghallughara Diwas”, the 29th Anniversary of Operation Bluestar, in Amritsar on June 5, 2013. The 1984 assault on the Golden Temple complex by the Indian army was conducted in an attempt to arrest separatists Sikh leader Sant Jarnail Singh Bhindranwale and his militant followers who had initiated a movement for a separate Sikh state. (Photo by Narinder Nanu/AFP Photo)

Indian Muslim children hold anti-US placards as they participate in a protest meeting against the film “Innocence of Muslims” in Kolkata on October 5, 2012. A low-budget, US-produced “Innocence of Muslims” movie has incited a wave of bloody anti-US violence in Libya, Egypt, Sudan, Tunisia, Yemen and in several other countries across the Muslim world. (Photo by Dibyangshu Sarkar/AFP/AFP Photo)

A car “crashed” into the ground at Hackescher Markt in Berlin, Germany on November 15, 2016, ahead of the launch of Jeremy Clarkson, Richard Hammond and James May's new show, “The Grand Tour”, on Amazon Prime Video, on Friday. (Photo by Clemens Bilan/Getty Images for Amazon Prime Video)

Men dressed as soldiers pose with models before the opening of the Gamescom 2013 fair in Cologne,Germany, on August 23, 2013. The Gamescom convention is Europe's largest video games trade fair. (Photo by Ina Fassbender/Reuters)

The chariot of God Bhairab is pulled through the city centre of Bhaktapur near Kathmandu during the Bisket festival April 10, 2015. The festival, which runs for more than a week and coincides with the Nepalese New Year, involves devotees offering prayers and the pulling of two chariots, one carrying the idol of God Bhairab and the other with the idol of Goddess Bhadrakali, around the ancient city of Bhaktapur. Devotees participate in the festival with the belief that they will be blessed with good health, fortune and harvest for the coming year. (Photo by Navesh Chitrakar/Reuters)

A hostage runs towards a police officer outside Lindt cafe, where other hostages are being held, in Martin Place in central Sydney December 15, 2014. Two more hostages have run out of the cafe at the center of a siege in Sydney, Australia's largest city, according to a Reuters witness at the site. The two women were both wearing aprons indicating they were staff at the Lindt cafe where a gunman has been holding an unknown number of hostages for several hours. Three men had earlier run out of the cafe. (Photo by Jason Reed/Reuters)