def fetch_sensor_names(pattern, client, log):
    """Fetch matching sensor names for a specified pattern. 
       
       Args:
           pattern (str): pattern to match.
           client (obj): KATPortalClient object.
           log: logger

       Returns:
           sensor_names (dict): sensor names matching supplied pattern.
           None if no sensor results obtainable. 
    """
    log.info("Checking for sensor pattern: {}".format(pattern))
    try:
        sensor_names = yield client.sensor_names(pattern)
        #if not sensor_names:
        #    log.warning("No matching sensors found for {}".format(pattern))
        #    return(None)
        #else:
        log.info("Match for telstate endpoint sensor: {}".format(sensor_names))
        #    return(sensor_names)
    except Exception as e:
        log.error(e)
        return(None)