code: def get_http_headers(user_agent=None, referer=None, accept_language=None):
      
  
      if user_agent is None:
          user_agent = settings.default_user_agent
      if referer is None:
          referer = settings.default_referer
      if accept_language is None:
          accept_language = settings.default_accept_language
  
      headers = requests.utils.default_headers()
      headers.update({'User-Agent': user_agent, 'referer': referer, 'Accept-Language': accept_language})
      return headers
docs: Update the default requests HTTP headers with OSMnx info.
  
      Parameters
      ----------
      user_agent : str
          the user agent string, if None will set with OSMnx default
      referer : str
          the referer string, if None will set with OSMnx default
      accept_language : str
          make accept-language explicit e.g. for consistent nominatim result sorting
  
      Returns
      -------
      headers : dict