A staff member (R) looks on next to a cake, which was baked in the shape of a muscular man, for customers to try for free during a promotional event of a cake store in Shenyang, Liaoning province, China, December 6, 2015. (Photo by Reuters/Stringer)

An AH-64D Apache attack helicopter flies in front of a wall of fire during the South Carolina National Guard Air and Ground Expo at McEntire Joint National Guard Base, South Carolina, U.S. on May 6, 2017. (Photo by Jorge Intriago/Reuters/Courtesy Air National Guard)

A man watches Israeli Air Force planes fly over the Mediterranean Sea from a beach at Tel Aviv during an aerial show as part of celebrations for Israel's Independence Day to mark the 66th anniversary of the creation of the state, May 6, 2014. (Photo by Nir Elias/Reuters)

Smithsonian National Zoo biologist Leigh Pitsko releases a male lion cub for its swim test in the zoo habitat moat, in Washington May 6, 2014. Four, unnamed ten-week old lion cubs were tested today for their ability to swim and remove themselves from their zoo habitat moat. (Photo by Gary Cameron/Reuters)

Promotional models use their smartphones during their break at the Global Mobile Internet Conference in Beijing May 6, 2014. Mobile Internet industry executives, developers and investors from more than 30 countries took part in the Global Mobile Internet Conference in Beijing, the organiser said. (Photo by Kim Kyung-Hoon/Reuters)

Officers react at their graduation ceremony during Iraqi Army Day anniversary celebration in Baghdad January 6, 2015. Iraqi Defence Minister Khaled al-Obeidi said on Tuesday that the Iraqi military has started rebuilding after its near total collapse last summer but that the effort is still in its initial phase. (Photo by Ahmad Mousa/Reuters)

A 42-day-old white bengal tiger cub (bottom), the first of its kind born in Peru, sleeps between toys as he is presented at the Huachipa's zoo in Lima on August 6, 2013. (Photo by Ernesto Benavides/AFP Photo)

Servicemen of “Kiev 12” military defence battalion react as they take part in a welcoming ceremony in central Ukrainian capital Kiev December 6, 2014. Servicemen of the battalion returned to Kiev after taking part in fighting in eastern Ukraine. (Photo by Gleb Garanich/Reuters)