A young man, who says he is part of a local criminal gang, poses for a picture holding a gun in the neighbourhood of Korogcho in Nairobi, Kenya, March 19, 2015. Around 2 million people live in the shantytowns packed in around Kenya's capital. Crime is high amid chronic unemployment levels, while basic services and sanitation are scarce. Residents try to make the best of things, eking out a living and picking up work where they can. (Photo by Siegfried Modola/Reuters)

Mario Huettenhofer, chief of the German company 3D Fab, presents his own face as 3d print during the international fairs FabCon 3.D and Rapid.Tech in Erfurt, Germany, Thursday, May 15, 2014. 130 exhibitors from all over the world present the entire world of 3D printing. The trade fairs are accompanied by specialist programs featuring 80 scientists, practitioners and trend analysts from ten countries, who will explain the latest findings, trends and applications for additive processes in industry and for 3D printing in the private sector to newcomers, experts and consumers alike. (Photo by Jens Meyer/AP Photo)

In this photo taken with long time exposure, a woman wears a hat at Churchill Downs before the 145th running of the Kentucky Derby horse race Saturday, May 4, 2019, in Louisville, Ky. (Photo by Charlie Riedel/AP Photo)

A handout photo made available by the World Press Photo (WPP) organization on 13 February 2017 shows a picture by Rossiya Segodnya photographer Valery Melnikov that won the Long-Term Projects – First Prize award of the 60th annual World Press Photo Contest, it was announced by the WPP Foundation in Amsterdam, The Netherlands on 13 February 2017. Caption: Civilians escape from a fire at a house destroyed by an air attack in the Luhanskaya village. (Photo by Valery Melnikov/EPA/Rossiya Segodnya/World Press Photo)

“A Mothers Tail”. A baby cub pulls on his mother's tail to get attention. Photo location: Masai Mara, Kenya. (Photo and caption by Tori Marsh/National Geographic Photo Contest)

Dayane Mello attends the photocall for the television miniseries “The Young Pope” at the 73rd Venice Film Festival in Venice, Italy, September 3, 2016. (Photo by Alessandro Bianchi/Reuters)

A cadet lies on the grass after collapsing during a promotion ceremony at a police school in Bogota December 7, 2012. (Photo by John Vizcaino/Reuters)

A woman uses a virtual reality (VR) headset to view images by Mexican painter Frida Kahlo in Mexico City, Mexico, 23 May 2018. The technological giant Google launched the “The Faces of Frida”, an interactive digital exhibition that treasures the heartrending work of the Mexican artist to tell her story from different points of view, with attention to the invisible details. (Photo by Sashenka Gutierrez/EPA/EFE)