private Map<Thread, Map<String, Object>> threadSpecificsProperties;
private PluginsManager() {
compositePersistenceDriver = new CompositePersistenceDriver(new RAMPersistenceDriver(),
new CachePersistenceDriver(new EmbbedXMLDocumentPersistenceDriver()),
new CachePersistenceDriver(new AnnotationPersistenceDriver()));
rootPersistenceDriver = new EquivalentsPersistenceDriver(compositePersistenceDriver);