docs: def get_config_file(override_files=False):
      """
      Looks for the most specific configuration file available.  An override
      can be provided as a string if needed.
      """
      if override_files:
          if isinstance(override_files, six.string_types):
              possible_configs = [override_files]
          else:
              raise Exception("Config file override must be a string")
      else:
          xdg_config_home = os.environ.get('XDG_CONFIG_HOME') or \
              os.path.expanduser('~/.config')
          possible_configs = [os.path.join(xdg_config_home, "supernova"),
                              os.path.expanduser("~/.supernova"),
                              ".supernova"]
  
      for config_file in reversed(possible_configs):
          if os.path.isfile(config_file):
              return config_file
  
      return False