'Log a message
@param severity: the severity of the message
@param message: the message
@param value: message suffix (optional)'

@staticmethod
def _log(severity, message, value=None):

    logger = logging.getLogger(__name__)
    logger.propagate = False
    msg = (('%s:    %s' % (message, value)) if value else message)
    extra = {'caller': 'S3LOG'}
    if current.deployment_settings.get_log_caller_info():
        caller = logger.findCaller()
        if caller:
            extra = {'caller': ('(%s    %s    %s)' % caller)}
    logger.log(severity, msg, extra=extra)
    return
