Food is placed on the tomb of pet dog Xixi at Baifu pet cemetery ahead of the Qingming Festival on the outskirts of Beijing, China March 26, 2016. The Chinese characters on the gravestone read: “Mommy's only good son”. (Photo by Jason Lee/Reuters)

Joe Deedon, president of TAC ONE Consulting, demonstrates searching for a shooter in a middle school during an Active Shooter Response course offered by TAC ONE in Denver April 2, 2016. According to TAC ONE, the course, which is offered for the first time to concealed weapons permit carrying civilians, is designed at preparing people to effectively save lives prior to the arrival of law enforcement at an active shooter incident. (Photo by Rick Wilking/Reuters)

Two pins featuring former North Korean leader Kim Il Sung wearing different facial expressions are displayed in a glass case of Thomas Hui at his apartment in Hong Kong, China April 11, 2016. Collector Thomas Hui, 37, a former bank employee in Hong Kong, who is fascinated by North Korean pins and badges, has gathered over 100 featuring former leaders Kim Il Sung and Kim Jong Il, and has been buying and trading these Communist accessories since 2008. (Photo by Bobby Yip/Reuters)

Brett Throckmorten of Barnes Bullets shows Logan Wingo how to sight down an electronic rifle in the trade booth area during the National Rifle Association's annual meeting in Nashville, Tennessee, April 11, 2015. (Photo by Harrison McClary/Reuters)

A mascot of the Philippine National Police (PNP), named after their Chief Director General Ronald Dela Rosa, marches with members of the K9 units and the Special Action Force before the mass blessing for rescue dogs during the celebration of the feast day of St. Francis of Assisi, patron Saint of Animals, at the St. John Paul II parish church in Eastwood, Quezon city, metro Manila, Philippines October 2, 2016. (Photo by Romeo Ranoco/Reuters)

Singer, songwriter, actress and philanthropist Miley Cyrus, L, takes a selfie while doing her signature tongue-out pose with GMU students Samaria Moss, 18, C, of Spottsylvania, VA, Jaide Tarwid, 18, from Wisconsin, and Zimuzo Okala, 19, of Chesapeake, VA, (blocked) as Cyrus makes a campaign visit for Hillary Clinton and Tim Kaine in Northern Virginia at George Mason University on Saturday, October 22, 2016 in Fairfax, VA. (Photo by Jahi Chikwendiu/The Washington Post)

A resident gestures about the loss of his home following an overnight fire at the Addition Hills area in suburban Mandaluyong city east Manila, Philippines, Monday, November 14, 2016. Fire officials say the overnight fire destroyed hundreds of homes, rendered more than 5,000 people homeless and resulted in the death of two residents. (Photo by Bullit Marquez/AP Photo)