@Override
  public void removeListener(final IZyNodeRealizerListener<?> listener) {
    m_listeners.removeListener(listener);
  }
Returns the user data associated with the realizer.

@return The user data associated with the realizer.
java/zylib/src/main/java/com/google/security/zynamics/zylib/yfileswrap/gui/zygraph/realizers/ZyGroupNodeRealizer.java