code: def log(self, level, msg):
          
          self._check_session()
          level = level.upper()
          allowed_levels = ('INFO', 'WARN', 'ERROR', 'FATAL')
          if level not in allowed_levels:
              raise ValueError('level must be one of: ' +
                               ', '.join(allowed_levels))
          self._rest.post_request(
              'log', None, {'log_level': level.upper(), 'message': msg})
docs: Write a diagnostic message to a log file or to standard output.
  
          Arguments:
          level -- Severity level of entry.  One of: INFO, WARN, ERROR, FATAL.
          msg   -- Message to write to log.