The Mercedes-Benz F015 Luxury in Motion autonomous concept car is shown on stage during the 2015 International Consumer Electronics Show (CES) in Las Vegas, Nevada January 5, 2015. (Photo by Steve Marcus/Reuters)

People in costume take photos during a Halloween event on October 31, 2015 in Lan Kwai Fong, Central District, Hong Kong. Halloween, a named taken from 'All Hallows' Even' falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Jerome Favre/Getty Images)

Attendees look at Volkswagen's BUDD-e, a long distance electric vehicle, displayed during a press event at CES 2016 at The Chelsea at The Cosmopolitan of Las Vegas on January 5, 2016 in Las Vegas, Nevada. CES, the world's largest annual consumer technology trade show, runs from January 6-9 and is expected to feature 3,600 exhibitors showing off their latest products and services to more than 150,000 attendees. (Photo by David Becker/Getty Images)

An Afghan National Army (ANA) helicopter flies over a soldier during a training exercise at the Kabul Military Training Centre in Afghanistan October 7, 2015. (Photo by Ahmad Masood/Reuters)

Police, bystanders and soldiers aid a fallen soldier at the War Memorial as police respond to an apparent terrorist attack on October 22, 2014 in Ottawa, Canada. A gunman is believed to have shot a soldier as he was standing guard at the National War Memorial in Ottawa. It is believed police then chased the man into the main parliament building at Parliament Hill, where more shots were fired. (Photo by Wayne Cuddington/Postmedia/Barcroft Media/ABACAPress)

A leopard trapped in a well looks up to forest officials on the premises of the Kamakhya temple in Gauhati, India, Thursday, April 4, 2013. According to locals, the leopard fell into the well while scouring for food. (Photo by Anupam Nath/AP Photo)

Handguns turned in from the public as part of the “Gun Turn-in” event where a $100 gift card is given for every firearm and a $10 gift card for each BB-gun, air-gun, or replica firearm turned over to police at Universal Missionary Baptist Church in Chicago, Illinois, U.S. May 28, 2016. (Photo by Jim Young/Reuters)

Punk protest band p*ssy Riot member Maria Alyokhina is detained by police at a protest in central Moscow February 24, 2014. Russian riot police detained over a hundred protesters, including two members of p*ssy Riot, on Monday at a Moscow courthouse where seven opponents of President Vladimir Putin were jailed from two and a half to four years over a demonstration that turned violent. (Photo by Maxim Shemetov/Reuters)