Militant Islamist fighters take part in a military parade along the streets of Syria's northern Raqqa province June 30, 2014. The fighters held the parade to celebrate their declaration of an Islamic “caliphate” after the group captured territory in neighbouring Iraq, a monitoring service said. The Islamic State, an al Qaeda offshoot previously known as Islamic State in Iraq and the Levant (ISIL), posted pictures online on Sunday of people waving black flags from cars and holding guns in the air, the SITE monitoring service said. (Photo by Reuters/Stringer)

A radio-controlled flying witch makes a test flight past a moon setting into clouds along the pacific ocean in Carlsbad, California October 8, 2014. Reuters was invited to photograph the testing of the life sized device by inventor Otto Dieffenbach lll. (Photo by Mike Blake/Reuters)

Commuters ride on the roof of a Jakarta state rail train at Cawang train station on January 27, 2012 in Jakarta, Indonesia. (Photo by Ulet Ifansasti/Getty Images)

Gina Labianca (L) tries on a super woman outfit as Charlie Lucas tries a snow white Costume at the Halloween MegaStore Miami Beach on October 21, 2011 in Miami Beach, Florida. The megastore is a temporary location for the store which opened for the holiday to sell costumes, masks and other items to people needing to dress up for the evening of October 31 when costumed people around the world observe the day. (Photo by Joe Raedle/Getty Images)

A woman struggles with an umbrella in the wind and rain while walking in Derby city centre, on December 23, 2013. (Photo by Rui Vieira/PA Wire)

A man sits waiting for a train on the London Underground in 1890, when the platform floors were still made from wooden floorboards. (Photo by Hi-Story/Alamy Stock Photo)

In this April 4, 2017 photo keeper German Alonso straps a leg prothesis to on the left leg of secretarybird Soeckchen (Sagittarius seprentarius) at the bird park in Walsrode, northern Germany. The prothesis was made in a 3D-printer after his left leg was amputated. (Photo by Philipp Schulze/DPA via AP Photo)

An “asparagus eating contest” made of asparagus and carved pumpkins is on display on the sidelines of the Giant Vegetable Competition in Klaistow, northeastern Germany, on September 20, 2015. The vegetable giants compete in seven categories. (Photo by Bernd Settnik/AFP Photo)