code: def download_needed(self, response, outfile, quiet=True):
          
          try:
              remote_date = datetime.strptime(response.headers['Last-Modified'],
                                              '%a, %d %b %Y %X %Z')
              if isfile(outfile):
                  local_date = datetime.fromtimestamp(os.path.getmtime(outfile))
                  if remote_date <= local_date:
                      if not quiet:
                          print(os.path.basename(outfile) +
                                ': Skipping, found more recently modified local '
                                'copy (use --force to force download)')
                      return False
          except:
              pass
          return True
docs: determine if a download is needed based on timestamp. Return True
              if needed (remote is newer) or False if local is newest.
               Parameters
              ==========
              response: the response from the API
              outfile: the output file to write to
              quiet: suppress verbose output (default is True)