Labourers work at the installation site of Liquefied Petroleum Gas (LPG) pipeline on May Day or Labour Day in Chandigarh, India, May 1, 2015. (Photo by Ajay Verma/Reuters)

In this photo provided by Jean Revillard, Solar Impulse 2, a plane powered by the sun's rays and piloted by Andre Borschberg, approaches Kalaeloa Airport near Honolulu, Friday, July 3, 2015. His 120-hour voyage from Nagoya, Japan broke the record for the world's longest nonstop solo flight, his team said. (Photo by Jean Revillard/Global Newsroom via AP Photo)

New Orleans police officers try to keep their heads down as they move in on a Black Panther headquarters during an exchange of gunfire in New Orleans on September 15, 1970. The shootout occurred as police moved in to make arrests on Tuesday morning following a series of incidents. (Photo by Jack Thornell/AP Photo)

A female sniper of the Syrian Democratic Forces (SDF) monitors the area during a celebration at the iconic Al- Naim square in Raqa on October 19, 2017, after retaking the city from Islamic State (IS) group fighters. The SDF fighters flushed jihadist holdouts from Raqa' s main hospital and municipal stadium, wrapping up a more than four- month offensive against what used to be the inner sanctum of IS' s self- proclaimed “caliphate”. (Photo by Bulent Kilic/AFP Photo)

In this Saturday, December 30, 2017, picture a girl wearing a bear fur costume takes part in an annual bear parade in Comanesti, Romania. It's a tradition that originated in pre-Christian times, when dancers wearing colored costumes or animal furs went from house to house in villages, singing and dancing to ward off evil. (Photo by Vadim Ghirda/AP Photo)

North Korean cheerleaders arrive at a rest stop, or service station, as their bus convoy carrying a 280- member delegation on its way to the 2018 Pyeongchang winter Olympic games, makes its way past Gapyeong on February 7, 2018 More than 200 young North Korean women arrived in South Korea to root for athletes from both sides of the peninsula at the Winter Olympics. (Photo by Ed Jones/AFP Photo)

In this November 3, 2015 file photo, Afghan Taliban fighters listen to Mullah Mohammed Rasool, the newly-elected leader of a breakaway faction of the Taliban, in Farah province, Afghanistan. Despite US President Donald Trump’s pronouncement that there would be no talks with the Taliban following a series of deadly attacks in Kabul, officials say talks continue, but neither side trusts the other and neither believes the other negotiates independently. (Photo by AP Photo/Stringer)

Model Heidi Klum in front of Concorde jet after arriving for Victoria's Secret fashion show at Cannes Film Festival on May 16, 2000. (Photo by Marion Curtis/DMI/The LIFE Picture Collection/Getty Images)