code: def root_directory(self):
          
          if not QgsApplication.qgisSettingsDirPath() or (
                  QgsApplication.qgisSettingsDirPath() == ''):
              self._root_directory = None
          else:
              # noinspection PyArgumentList
              self._root_directory = os.path.join(
                  QgsApplication.qgisSettingsDirPath(),
                  'inasafe')
  
          return self._root_directory
docs: Map the root directory to user profile/inasafe so the minimum needs
             profile will be placed there (user profile/inasafe/minimum_needs).
  
          :returns: root directory
          :rtype: QString