public Set<Host> getHosts(Database catalog_db) {
Set<Host> hosts = new HashSet<Host>();
for (String host_key : this.getHosts()) {
Host catalog_host = CatalogKey.getFromKey(catalog_db, host_key, Host.class);
assert (catalog_host != null);
hosts.add(catalog_host);
} // FOR
return (hosts);
}
