code: def get_uvi_history(self, params_dict):
          
          lat = str(params_dict['lat'])
          lon = str(params_dict['lon'])
          start = str(params_dict['start'])
          end = str(params_dict['end'])
          params = dict(lat=lat, lon=lon, start=start, end=end)
  
          # build request URL
          uri = http_client.HttpClient.to_url(UV_INDEX_HISTORY_URL,
                                              self._API_key,
                                              None)
          _, json_data = self._client.cacheable_get_json(uri, params=params)
          return json_data
docs: Invokes the UV Index History endpoint
  
          :param params_dict: dict of parameters
          :returns: a string containing raw JSON data
          :raises: *ValueError*, *APICallError*