'Returns a set of flexvol names.'

def _get_flexvol_names_from_hosts(self, hosts):

    flexvols = set()
    for host in hosts:
        pool_name = volume_utils.extract_host(host, level='pool')
        flexvol_name = pool_name.rsplit('/', 1)[1]
        flexvols.add(flexvol_name)
    return flexvols
