if (restrictedClass == null)
restrictedClass = database.getMetadata().getSchema().createAbstractClass(RESTRICTED_CLASSNAME);
if (!restrictedClass.existsProperty(ALLOW_ALL_FIELD))
restrictedClass.createProperty(ALLOW_ALL_FIELD, OType.LINKSET, database.getMetadata().getSchema()
.getClass(IDENTITY_CLASSNAME));
if (!restrictedClass.existsProperty(ALLOW_READ_FIELD))
restrictedClass.createProperty(ALLOW_READ_FIELD, OType.LINKSET,
database.getMetadata().getSchema().getClass(IDENTITY_CLASSNAME));
if (!restrictedClass.existsProperty(ALLOW_UPDATE_FIELD))
restrictedClass.createProperty(ALLOW_UPDATE_FIELD, OType.LINKSET,
database.getMetadata().getSchema().getClass(IDENTITY_CLASSNAME));