A participant works on a laptop on the first day of the 28th Chaos Communication Congress (28C3) – Behind Enemy Lines computer hacker conference on December 27, 2011 in Berlin, Germany. The Chaos Computer Club is Europe's biggest network of computer hackers and its annual congress draws up to 3,000 participants. (Photo by Adam Berry/Getty Images)

A flight attendant wearing a Brazil soccer team jersey demonstrates the emergency mask on an airplane travelling from Kunming to Hangzhou June 23, 2014. A Chinese airline company renovated the cabin of one of its flights then dressed the flight attendants with soccer jerseys as a way to celebrate the 2014 Brazil World Cup and hoping to attract more customers, local media reported. (Photo by Wong Campion/Reuters)

Ethiopian Airlines female pilots prepare the plane before takeoff at Bole international airport in the capital Addis Ababa, November 19, 2015. Ethiopia Airlines on Thursday, dispatched its first ever all-female operated flight. Every aspect of the journey was handled by women, from the ground crew, aircraft maintenance to traffic controllers. Gualu and her co-pilot were charged with flying the crew and passengers to Bangkok, Thailand. (Photo by Tiksa Negeri/Reuters)

A woman attends a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. Women have boxed as long as the sport has existed but for years they were relegated out of national and international competitions in many countries around the world. Female boxers entered the ring in an exhibition match at the 1904 Olympic Games, but it was more than a century later when they were given the green light to make their Olympic debut in London in 2012. (Photo by Carlos Barria/Reuters)

A Toy Poodle is groomed at the benching area before competition at the 139th Westminster Kennel Club's Dog Show in the Manhattan borough of New York February 16, 2015. (Photo by Mike Segar/Reuters)

Members of the local Cossack community undergo military training at a boot camp set up by the Russkiye Vityazi (Russian Knights) military patriotic club in the village of Sengileyevskoye, south of Stavropol, March 22, 2015. A group of cossacks from the village of Kazanskaya, who are planning a professional career at the military intelligence service, has arrived at a camp for training under the leadership of professional instructors. (Photo by Eduard Korniyenko/Reuters)

Prospective flight attendants listen to their instructor during an etiquette training course at Indigo Airlines' Ifly training centre in Gurgaon on the outskirts of New Delhi November 18, 2014. (Photo by Adnan Abidi/Reuters)

Family of passengers onboard AirAsia flight QZ8501 react at a waiting area in Juanda International Airport, Surabaya December 28, 2014. Indonesia's air force was searching for the AirAsia plane carrying 162 people that went missing on Sunday after the pilots asked to change course to avoid bad weather during a flight from the Indonesian city of Surabaya to Singapore. The Airbus 320-200 lost contact with Jakarta air traffic control at 6:17 a.m. (23:17 GMT), officials said. (Photo by Reuters/Beawiharta)