FileDataSource dataSource = new FileDataSource();
dataSource.setAlwaysCreateFiles(true);

FileIdentityStoreConfiguration configuration = new FileIdentityStoreConfiguration();

// add the realms that should be supported by the file store
configuration.addRealm(Realm.DEFAULT_REALM);
configuration.addRealm("Testing");

configuration.setDataSource(dataSource);

FeatureSet.addFeatureSupport(configuration.getFeatureSet());
FeatureSet.addRelationshipSupport(configuration.getFeatureSet());
FeatureSet.addRelationshipSupport(configuration.getFeatureSet(), CustomRelationship.class);
FeatureSet.addRelationshipSupport(configuration.getFeatureSet(), Authorization.class);
configuration.getFeatureSet().setSupportsCustomRelationships(true);
configuration.getFeatureSet().setSupportsMultiRealm(true);

config.addStoreConfiguration(configuration);

IdentityManager identityManager = new DefaultIdentityManager();
//Config is an instance of FileIdentityStoreConfiguration
identityManager.bootstrap(config, new DefaultIdentityStoreInvocationContextFactory(null));