Boys walk home for lunch from school in the village of Kogelo, west of Kenya's capital Nairobi, July 16, 2015. U.S. President Barack Obama visits Kenya and Ethiopia later this month. His ancestral home of Kogelo is home to Sarah Hussein Obama, his step-grandmother. The Kenyan village, burial place of Obama's father, features an open-pit goldmine, a pork butcher's, a school named after their most famous son and outdoor market stalls. Villagers get around by motorbike taxi or on foot while a donkey-cart transports water. Children, some of them named Obama in honour of the President, walk to and from school together. (Photo by Thomas Mukoya/Reuters)

A man covered in motor oil, poses for a picture next to a girl dress a traditional clothes during a festivities in honor of Santo Domingo de Guzman in Managua, Nicaragua, Saturday, August 1, 2015. Some of the faithful coat their bodies in a black motor oil, red paint and wear traditional clothes as a promise for a prayer or miracle they believe was performed or answered by Managua's patron saint, Santo Domingo de Guzman. (Photo by Esteban Felix/AP Photo)

People stand near beached sperm whales on January 13, 2016, after they became stranded on the Dutch island of Texel the day before. Five sperm whales which became stranded on Texel have died, officials said January 13. Experts said the beached whales had already been badly injured and their chances of survival were poor. Volunteers tried to save them but called off their efforts late in the night because of bad weather and darkness, ANP news agency said. (Photo by Remko de Waal/AFP Photo/ANP)

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)

African migrants stranded in Costa Rica walk near garbage on the Inter-American highway at the border between Costa Rica and Nicaragua, in Penas Blancas, Costa Rica, September 8, 2016. (Photo by Juan Carlos Ulate/Reuters)

A model presents a creation by Australian designers Tamara Ralph and Michael Russo as part of their Haute Couture Spring/Summer 2017 fashion show for Ralph & Russo in Paris, France January 23, 2017. (Photo by Gonzalo Fuentes/Reuters)

A girl reacts as coloured water is thrown on her face while celebrating Holi, the Festival of Colours, in Mumbai, India, March 13, 2017. (Photo by Shailesh Andrade/Reuters)

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)