if (config != null) {
String acl_semantics = config.getParameter(ACL_SEMANTICS);
if ((acl_semantics != null) && (acl_semantics.equals(LEGACY_ALL_GRANT_BEFORE_DENY ))) {
securityHelper = new SecurityImpl(namespace, namespace.getConfig());
} else if((acl_semantics != null) && (acl_semantics.equals(ALL_GRANT_BEFORE_DENY ))) {
securityHelper = new SecurityImplAllGrant(namespace, namespace.getConfig());
} else if (acl_semantics != null) {
try {
securityHelper = (Security) Class.forName(acl_semantics).newInstance();
if (securityHelper != null) {
securityHelper.init(namespace, namespace.getConfig());