// First check that the URI isn's null, if it is throw IllegalArgumentException
if (uri == null) throw new IllegalArgumentException("URI argument is null");
// OK, let's try to get the DigitalObjectManager
try {
dom = DataRegistryImpl.domSet.get(new PDURI(uri.normalize()).formDataRegistryRootURI());
// Catch the URI syntax thrown by PDURI if this isn't a valid ID URI, and rethrow as not found
} catch (URISyntaxException e) {
throw new DigitalObjectManagerNotFoundException("URI: " + uri +
" is not a valid Planets DataRegistry URI ID", e);
} catch (Exception e) {