docs: def _convert_time(self, time_str):
          """
          Convert a string representation of the time (as returned by blockr.io api) into unix
          timestamp
  
          :param time_utc_str: string representation of the time
          :return: unix timestamp
          """
          dt = datetime.strptime(time_str, "%Y-%m-%dT%H:%M:%SZ")
          return int(time.mktime(dt.utctimetuple()))