The crowd watches as stunt pilots Melissa Pemberton, Jurgis Kairys and Skip Stewart of The Immortals fly past pyrotechnics as they perform at The Australian International Airshow on March 1, 2015 in Avalon, Australia. (Photo by Scott E. Barbour/Getty Images)

2000 attended a welcome party at TigerTiger Manchester which was the first event in set of big club night for new students to Manchester and Salford universities in Manchester, UK on September 19, 2016. This year, university bosses have stepped up security in Manchester. (Photo by Jordan Sinclair/UK News Pictures)

A woman walks behind the installation “Wandering boy is forever attractive” (1985) by Tetsumi Kudo during the press preview at the exhibition “Tetsumi Kudo – Retrospective” in the Fridericianum in Kassel, Germany, Friday, September 23, 2016. The exhibition offers an in-depth, comprehensive view of works by the Japanese artist Kudo. It starts on Sept. 25, 2016 and lasts until Jan. 1, 2017. (Photo by Jens Meyer/AP Photo)

Canada's Marissa Papaconstantinou makes her way to the finish line after falling in the Women's 200m T44 Final during day ten of the IPC World ParaAthletics Championships 2017 at London Stadium on July 23, 2017 in London, England. (Photo by Peter Cziborra/Reuters)

Ireland's Philip Mulpeter, left, is kicked by Brazilian Vitor Nobrega during their welterweight mixed martial arts bout of International Pro Combat at the Estoril Casino in Estoril, near Lisbon, Portugal, Monday, January 26, 2015. Nobrega defeated Mulpeter. (Photo by Francisco Seco/AP Photo)

Real life doll Alina Kovalevskaya poses for a photograph on May 29, 2014 in Odessa, Ukraine. Alina Kovalevskaya is a walking, talking, breathing living doll on the lookout for her real-life Ken. The 21-year-old is from Odessa, Ukraine – the same city as real-life Barbie Valeria Lukyanova, who has made headlines around the world for her unique look and controversial opinions. The pair were friends, but their relationship has since soured. Alina has made a splash online, with her YouTube videos showing off her doll-like charms attracting hundreds of thousands of views. (Photo by Aleksey Solodunov/Barcroft Media)

Four year old Kaleb Stanley (R), from Dublin, reaches up to puncture a giant bubble with the help of his seven year old brother Jacob on London's South Bank on May 9, 2008 in England. (Photo by Peter Macdiarmid/Getty Images)

An Armatix employee holds a “smart gun” by the company at the Armatix headquarters in Munich May 14, 2014. The gun is implanted with an electronic chip that allows it to be fired only if the shooter is wearing a watch that communicates with it through a radio signal. If the gun is moved more than 10 inches (25 cm) from the watch, it will not fire. A Maryland gun shop owner has dropped his plan to be the first in the United States to sell the so-called “smart gun” after a backlash that included death threats. (Photo by Michael Dalder/Reuters)