code: def get_recent_files(self):
          
          try:
              recent_files = self.CONF[WORKSPACE].get('main', 'recent_files',
                                                      default=[])
          except EnvironmentError:
              return []
  
          for recent_file in recent_files[:]:
              if not os.path.isfile(recent_file):
                  recent_files.remove(recent_file)
          return list(OrderedDict.fromkeys(recent_files))
docs: Return a list of files opened by the project.