A visitor stands in the exhibition “I Am A Drop In The Ocean” dedicated to the artistic and visual expressions of the protests that shook the Ukraine from November 2013 until February 2014 at the Kuenstlerhaus gallery in Vienna, Austria, Thursday, April 10, 2014. The exhibition opens its doors from April 11 until May 23, 2014. (Photo by Ronald Zak/AP Photo)

Members of the Bolivian combined forces of army and police rest at their headquarters at the end of their ceremony for the task of fighting against drugs and the eradication of coca leaves in Chimore, east of La Paz, December 10, 2014. The government of Bolivia's President Evo Morales eradicated some 11,000 hectares of illegal coca plants and confiscated nearly 192 tons of drugs in 2014, according to the local media. (Photo by David Mercado/Reuters)

An undercover police officer, who had been marching with anti-police demonstrators, aims his gun at protesters after some in the crowd attacked him and his partner in Oakland, California December 10, 2014. Police said more than 100 demonstrators marched in Berkeley, California, which has a history of social activism. Under cloudy skies, turnout was smaller than earlier in the week, when demonstrators in the area threw rocks at police and shut down a major freeway. (Photo by Noah Berger/Reuters)

This image is NGC 6543 known as the Cat's Eye Nebula as it appears to the Chandra X-Ray Observatory and Hubble Telescope. A planetary nebula is a phase of stellar evolution that the sun should experience several billion years from now, when it expands to become a red giant and then sheds most of its outer layers, leaving behind a hot core that contracts to form a dense white dwarf star. This image was released October 10, 2012. (Photo by J. Kastner/NASA/CXC/RIT)

A German contestant adjusts his helmet during the “Battle of Nations” in Aigues-Mortes, southern France, Friday, May 10, 2013 where Middle Ages fans attend the historical medieval battle competition. The championship will be attended by 22 national teams, which is twice the number it was last year. The battle lasts until May 12. (Photo by Philippe Farjon/AP Photo)

An Indian woman collects camel dung during the annual cattle fair in Pushkar, in the western Indian state of Rajasthan, Sunday, November 10, 2013. Pushkar, located on the banks of Pushkar Lake, is a popular Hindu pilgrimage spot that is also frequented by foreign tourists who come to the town for the annual cattle fair and camel races. (Photo by Ajit Solanki/AP Photo)

A young Thai man jumps in the air and cheers as his rocket takes off at the Bun Bang Fai Rocket Festival on May 10, 2015 in Yasothon, Thailand. During the Bun Bang Fai rocket festival, Thai residents launch enormous home-made rockets into the air to gain Buddhist merit and to celebrate the beginning of the rainy season. (Photo by Taylor Weidman/Getty Images)

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)