An ethnic Armenian fighter carries Kalashnikov machine guns to his comrade-in-arms at Martakert province in the separatist region of Nagorno-Karabakh, Azerbaijan, Monday, April 4, 2016. (Photo by Vahan Stepanyan/PAN Photo via AP Photo)

A pistol set made by Versailles gunsmith Nicolas-Noel Boutet and was gifted to Simon Bolivar from Marquis de La-fayette is displayed at Christie's auction house in the Manhattan borough of New York, April 5, 2016. (Photo by Lucas Jackson/Reuters)

A visitor poses inside a three story upside-down family sized house at the Huashan Creative Park in Taipei, Taiwan April 7, 2016. Over 300 square meters of floor space of the upside-down house, filled with home furnishings, was created by a group of Taiwanese architects at a total cost of around US$600,000 and took 2 months to complete, according to the organisers. (Photo by Tyrone Siu/Reuters)

Korean War veteran Jon Sun Rye, 83 years old, walks after she paid respect to former leaders Kim Il-sung and Kim Jong-il at Mansu Hill in Pyongyang, North Korea, 15 April 2016. North Korea is marking the “Day of the Sun”, celebrating the day of birth of the country's founder, Kim Il-sung. The Day of the Sun is a national holiday. (Photo by Franck Robichon/EPA)

Julya Baer, 30, attends a candlelight vigil and celebration of Prince's life in Leimert Park in memory of musician Prince on April 21, 2016, in Los Angeles, California. Prince died earlier today at his Paisley Park compound at the age of 57. (Photo by Kevork Djansezian/Getty Images)

A woman walks past graffiti in Beirut, Lebanon, Wednesday, May 4, 2016. Graffiti artists have been trying to re-engage disillusioned youth in a debate about the country's latest wave of political turmoil. (Photo by Hassan Ammar/AP Photo)

A woman runs while another woman ducks down to avoid teargas as police disperse supporters of the opposition Coalition for Reforms and Democracy (CORD), led by former Prime Minister Raila Odinga, during a demonstration against Independent Electoral and Boundaries Commission (IEBC) in downtown Nairobi, Kenya, 09 May 2016. (Photo by Dai Kurokawa/EPA)

A spinning top is seen on a hand during a performance at Sanxia old street in New Taipei City, Taiwan May 8, 2016. Taiwan's ancient folk art of spinning tops is kept alive by a group of enthusiasts who perform intricate tricks with the toys at a temple in Taipei, the capital. (Photo by Tyrone Siu/Reuters)