code: protected void assertNotDisposed() {
      if (this.disposedFlag.get()) {
        final AlreadyDisposedError error = new AlreadyDisposedError("Object already disposed");
        MetaErrorListeners.fireError("Detected call to disposed object", error);
        throw error;
      }
    }
docs: Auxiliary method to ensure that the object is not disposed.
  
  @throws AlreadyDisposedError if the object has been already disposed, with notification of the global error listeners
  @since 1.0