final ZoneAndName securityGroupInZone = checkNotNull(securityGroupInZoneRef.get(), "securityGroupInZone");
Optional<? extends SecurityGroupApi> api = novaApi.getSecurityGroupExtensionForZone(securityGroupInZone.getZone());
checkArgument(api.isPresent(), "Security groups are required, but the extension is not available!");
logger.trace("looking for security group %s", securityGroupInZone.slashEncode());
try {
SecurityGroup returnVal = Iterables.find(api.get().list(), new Predicate<SecurityGroup>() {
@Override
public boolean apply(SecurityGroup input) {