(FILES) In this file photo taken on April 22, 2016 then German Chancellor Angela Merkel (L) and then Bavarian Minister for Economy Ilse Aigner (R) share a joke during the 500 years anniversary of the German beer purity requirements, in Ingolstadt, southern Germany. The current president of the Bavarian state parliament, 61-year-old Ilse Aigner (CSU), is being tipped to become Germany's first female president, according to sources close to the Christian conservative union. (Photo by CHRISTOF STACHE / AFP via Getty Images)