aux = this.read(entity.getClass(), entityId);
} catch (DataNotFoundException e) {
// An exception must be thrown, otherwise means the entity already exists in database
}
if (aux != null) {
throw new DuplicateInstanceException("The entity you try to save is already in the database! -> " + entity);
}
}
// Get the identifier when necessary
if (entityId == null && entity.getClass().getAnnotation(PersistentEntity.class).generateKey()) {