North Korean leader Kim Jong Un smiles as he attends a flight training session by female fighter pilots Jo Kum Hyang and Rim Sol in this undated photo released by North Korea's Korean Central News Agency (KCNA) on June 22, 2015. (Photo by Reuters/KCNA/Antara Foto)

People take pictures of 30 Rockefeller Plaza as it is lit in the colors of the Democratic and Republican parties ahead of the U.S presidential election in Manhattan, New York, U.S., November 7, 2016. (Photo by Andrew Kelly/Reuters)

This picture taken on October 20, 2016 shows students practising wushu at the Tagou martial arts school in Dengfeng. China is investing hugely in football training and has vowed to have 50 million school- age players by 2020, as the ruling Communist party eyes “football superpower” status by 2050. (Photo by Nicolas Asfouri/AFP Photo)

A pair of young visitors rushes through a tunnel of colored lights at the annual Garden of Lights display at Brookside Gardens on December, 06, 2015 in Silver Spring, MD. (Photo by Bill O'Leary/The Washington Post)

The moon rises over people gathered on Glastonbury Tor ahead of tomorrow's Blue Moon on July 30, 2015 in Somerset, England. The full moon appearing on July 31 will be what's called a Blue Moon, which refers to the second of two full moons appearing in the same calendar month. The last time this happened was in 2012 and there isn't due another until 2018. (Photo by Matt Cardy/Getty Images)

UConn students from Storrs, Conn., Gary Tu, Danny Wang and Victor Zheng, fish at Shenipsit Lake in Tolland, Conn. during sunset on Tuesday, August 19, 2014. (Photo by Jim Michaud/AP Photo/Journal Inquirer)

In this March 20, 2016 photo, Maj. Mohammed Hussein, an officer with Iraq's elite counterterrorism forces, shows a photo of a slain Islamic State group militant still wearing in a suicide vest, taken during fighting that freed the city of Ramadi from IS control earlier this year. As they fled, the militants destroyed some buildings and booby-trapped others with explosives, leaving behind an empty prize for government forces retaking the city. (Photo by Maya Alleruzzo/AP Photo)

Volunteers try to keep alive some of the hundreds of stranded pilot whales after one of the country's largest recorded mass whale strandings, in Golden Bay, at the top of New Zealand's south island, February 10, 2017. Volunteers in New Zealand managed to refloat about 100 surviving pilot whales on Saturday, February 11, 2017 and are hoping they will swim back out to sea after more than 400 of the creatures swam aground at a remote beach. (Photo by Ross Wearing/Reuters)