A technician holds a recently 3D printed replica of Darth Vader's melted helmet from “Star Wars: The Force Awakens”, in the Propshop headquarters at Pinewood Studios near London, Britain May 25, 2016. Propshop headquarters at Pinewood Studios is making limited edition replicas of Star Wars props. (Photo by Peter Nicholls/Reuters)

Sarah Bui poses for photographer, Brian Le around blossoming cherry trees, near the Tidal Basin on Thursday March 23, 2017 in Washington, DC. (Photo by Matt McClain/The Washington Post)

Iraqi paramilitary troops fire towards Islamic State militants during a battle with Islamic State militants on the outskirts of the ancient city of Hatra near Mosul,Iraq April 26, 2017. (Photo by Reuters/Stringer)

The main entrance and blast door at the nuclear bunker site on the Woodside Road industrial estate on February 4, 2016 in Ballymena, Northern Ireland. The underground shelter has been put up for sale by the offices of the Northern Ireland First and Deputy First Minister. The bunker which was completed in 1990 was built to hold up to 235 people in the event of a nuclear bomb and is complete with kitchen facilities, dormitories and decontamination chambers. The site, one of approximately 1,600 nuclear monitoring posts built in the UK since 1955, is on the housing market with an asking price of £575,000. (Photo by Charles McQuillan/Getty Images)

Emergency responders respond to the scene of a 565-foot-tall crane that toppled and flipped upside down, stretching along nearly two city blocks in downtown Manhattan in New York, February 5, 2016. The massive construction crane collapsed in lower Manhattan during a swirling snowstorm on Friday, killing one person and crushing a line of parked cars in the first accident of its kind in New York City since 2008. (Photo by Brendan McDermid/Reuters)

Performer from the Mangueira samba school parades during carnival celebrations at the Sambadrome in Rio de Janeiro, Brazil, Tuesday, February 9, 2016. (Photo by Silvia Izquierdo/AP Photo)

A Christian worshipper reacts as she takes part in the Christian Orthodox Holy Fire ceremony at the Church of the Holy Sepulchre in Jerusalem's Old City, April 30, 2016. (Photo by Amir Cohen/Reuters)

A woman sits on a terrace at Tiki hostel in Cantagalo favela, in Rio de Janeiro, Brazil, April 16, 2016. Hostels in a few of Rio's more than 1,000 slums serve not only as a cheap housing alternative for the more adventurous among the estimated 500,000 foreign tourists expected to arrive for the Olympics in August. The establishments also open up the rich culture of the city's shantytowns for travellers, giving them a glimpse into once “no-go” areas where about one-fifth of Rio's population lives. (Photo by Pilar Olivares/Reuters)