this.config = Preconditions.checkNotNull(config);
this.initialData = Preconditions.checkNotNull(initialData);
this.persistenceId = Preconditions.checkNotNull(persistenceId);
this.config = Preconditions.checkNotNull(config);
this.initialData = Preconditions.checkNotNull(initialData);
this.persistenceId = Preconditions.checkNotNull(persistenceId);