docs: def downloadFile(self, from_path, to_path = ''):
          """Download a file.
  
              >>> nd.downloadFile('/Picture/flower.png', '~/flower.png')
  
          :param from_path: The full path to download the file to, *including the file name*. If the destination directory does not yet exist, it will be created.
          :param to_path: The full path of a file to be saved in local directory.
  
          :returns: File object
          """
  
          if to_path == '':
              file_name = os.path.basename(from_path)
              to_path = os.path.join(os.getcwd(), file_name)
  
          url = nurls['download'] + from_path
  
          data = {'attachment':2,
                  'userid': self.user_id,
                  'useridx': self.useridx,
                  'NDriveSvcType': "NHN/ND-WEB Ver",
                 }
  
          if '~' in to_path:
              to_path = expanduser(to_path)
  
          with open(to_path, 'wb') as handle:
              request = self.session.get(url, params = data, stream=True)
  
              for block in request.iter_content(1024):
                  if not block:
                      break
                  handle.write(block)
              return handle