A sunflower “smiles” in a field in Tokyo on August 7, 2014. Some 20,000 sunflowers were enjoyed by visitors to the area this week. (Photo by Yoshikazu Tsuno/AFP Photo)

Residents of the Brussels suburb of Molenbeek are searched by police before taking part in a memorial gathering to honour the victims of the recent deadly Paris attacks, in Brussels, Belgium, November 18, 2015. (Photo by Yves Herman/Reuters)

Silver medalist Vivian Jepkemoi Cheruiyot of Kenya and gold medalist Almaz Ayana (R) of Ethiopia during the medal ceremony for the women's 10000m final of the Rio 2016 Olympic Games Athletics, Track and Field events at the Olympic Stadium in Rio de Janeiro, Brazil, 12 August 2016. (Photo by Sergei Ilnitsky/EPA)

Fighters of the Free Syrian Army fire an anti-aircraft weapon in the rebel-held Mashhad area in southeastern Aleppo, on December 12, 2016, as they battle Syrian government forces during an operation to retake the embattled city. The crucial battle for Aleppo entered its “final phase” after Syrian rebels retreated into a small pocket of their former bastion in the face of new army advances. The retreat leaves opposition fighters confined to just a handful of neighbourhoods in southeast Aleppo, the largest of them Sukkari and Mashhad. (Photo by AFP Photo/Stringer)

New York Sports Club Gets In The Election Spirit With Hillary Clinton And Donald Trump Boxing Inspired Class on October 27, 2016 in New York City. (Photo by Thos Robinson/Getty Images for DKC for New York Sports Clubs)

Apple CEO Steve Jobs delivers the keynote address at the 2011 Apple World Wide Developers Conference at the Moscone Center on June 6, 2011 in San Francisco, California. Apple CEO Steve Jobs returned from sick leave to introduce Apple's new iCloud storage system and the next versions of Apple's iOS and Mac OSX. (Photo by Justin Sullivan/Getty Images)

Pilgrims wearing traditional dresses take part during the Queen of Angeles pilgrimage in Alajar, southern Spain, September 8, 2015. Every year, devotees converge at the Arias Montano crag to pay homage to the Queen of Angeles during an annual pilgrimage which combines religious fervour and festive colour. (Photo by Marcelo del Pozo/Reuters)