In this Thursday, March 17, 2016 photo, 33-year-old Palestinian clown doctor Alaa Miqdad, left, entertains 3-year-old patient Yaqin Shawaf, who suffers from dialysis, in the department of kidney diseases at Al-Rantisi children's hospital in Gaza City. (Photo by Adel Hana/AP Photo)

A riot policeman watches as a police vehicle burns in Braamfontein, Johannesburg, South Africa, Tuesday, October 25, 2016. Rioters in South Africa set a police vehicle on fire Tuesday and stoned vehicles near a Johannesburg university that has been the scene of sometimes violent protests by students demanding free education. The violence broke out in streets near the University of the Witwatersrand at around the same time that student protesters met and marched off the campus, South African media reported. (Photo by Yeshiel Panchia/AP Photo)

A member of India’s Dongria tribe faints in trance during the two-day long Niyamraja Festival atop the Niyamgiri hills near Lanjigarh in Kalahandi district, Orissa state, India, Sunday, February 22, 2015. Every year, members of this indigenous group celebrate this festival sacrificing animals and birds in worship of their deity. (Photo by Biswaranjan Rout/AP Photo)

In this photo taken on Friday, July 14, 2017, a student at a paramilitary camp for children calls the rank to attention outside Kiev, Ukraine. As the deadly conflict in eastern Ukraine entered its third year, some parents in Ukraine are anxious to make sure their children are ready to fight it, instead of swimming and playing volleyball. (Photo by Efrem Lukatsky/AP Photo)

In this October 29, 2013 photo, Daniel smokes marijuana inside his apartment where he uses a hydroponics system to grow his weed in Mexico City. “I'm not a narco, dude. I just like to smoke”, said Daniel, who spoke on condition that his last name not be used because, he said, his home-grow operation is "super-illegal" despite being for personal use only. (Photo by Eduardo Verdugo/AP Photo)

Iranians flash the victory sign from their car while celebrating on a street in northern Tehran, Iran, Thursday, April 2, 2015, after Iran's nuclear agreement with world powers in Lausanne, Switzerland. The United States, Iran and five other world powers on Thursday announced an understanding outlining limits on Iran's nuclear program so it cannot lead to atomic weapons, directing negotiators toward achieving a comprehensive agreement within three months. (Photo by Ebrahim Noroozi/AP Photo)

In this photo provided by Rolex, jury members inspect a 1933 Duesenberg SJ Brunn Riviera Convertible Sedan owned by John D. Groendyke at the Rolex Monterey Motorsports Reunion during Monterey’s Classic Car Week, Sunday, August 17, 2014, in Carmel, Calif. (Photo by Tom O’Neal/AP Photo/Rolex)

Engine driver Josef Kowatsch (top L) steers a train through the NEAT Gotthard Base Tunnel during a media visit near the town of Erstfeld August 24, 2015. Crossing the Alps, the world's longest train tunnel should become operational at the end of 2016, consisting of two parallel single track tunnels, each of a length of 57 km (35 miles). (Photo by Arnd Wiegmann/Reuters)