A paper mache pig meant to mock Donald Trump sits on display at a protest against the Republican presidential candidate before the start of the Republican National Convention in Cleveland, Ohio, USA, 17 July 2016. Numerous protest groups are expected in Cleveland throughout the four-day-long convention. (Photo by Jim Lo Scalzo/EPA)

Breitling Wingwalkers aircrafts perform during an aerobatic display at an air show in Zhengzhou, Henan province, China, September 25, 201. (Photo by Reuters/Stringer)

Sharafkhaneh port and lake Urmia. Masoud Ghadiri (Iran). The summer Milky Way is very prominent in this photo. On the galaxy zone, Saturn is located besides the Lagoon nebula. On the right of the horizon, you can see the extreme light pollution of Urmia, which is caused by ever-increasing city development. (Photo by Masoud Ghadiri/National Maritime Museum)

A woman affected by tear gas is assisted during a May Day protest against austerity measures, in San Juan, Puerto Rico May 1, 2018. (Photo by Alvin Baez/Reuters)

Gunfire was brought to the steps of President Truman's Washington home, Blair House, as two assassins tried to kill the chief executive, November 1, 1950. One of the gunmen, Oscar Collazzo of New York, lay wounded at the bottom of Blair House's front steps after the president's police guard had finished their work, at the cost of one guards' life, Dec. 9, 1950. The second gunman was killed. (Photo by Harvey Georges/AP Photo)

Adolf Hitler (left), German Nazi politician, in a deck chair next to is niece Angela (Geli) Raubal – around 1930. (Photo by Ullstein Bild/Ullstein Bild via Getty Images)

A man carries a child in a wheelbarrow near a burning tire barricade in the framework of the protests of the last three days due to the increase in fuel prices, in Port-au-Prince, Haiti, 09 July 2018. Haiti was today practically paralyzed by a transport strike after three days of violent riots due to an increase in fuel prices, which the Government left without effect shortly after the announcement. The Prime Minister, Jack Guy Lafontant, today heads a meeting with representatives of Parliament to assess the situation created after the violent protests, which have left at least three dead and several injured. (Photo by Jean Marc Hervé Abelard/EPA/EFE)

Two cats watch a mouse walking on the pavement in Kuwait City on March 8,2017. (Photo by Yasser Al-Zayyat/AFP Photo)