}
public Collection<String> getCommonBlockDeviceNames(final Iterable<Host> hosts) {
Optional<Collection<String>> namesIntersection = Optional.absent();
for (final Host host : hosts) {
final HostBlockDevices hostBlockDevices = hostBlockDevicesByHost.get(host);
if (hostBlockDevices != null) {
namesIntersection = hostBlockDevices.getBlockDevicesNamesIntersection(namesIntersection);
}
}
return namesIntersection.or(new ArrayList<String>());
}