code: public void removeListener(ILabelProviderListener listener)
  	{
  		if (fListeners != null)
  		{
  			fListeners.remove(listener);
  			if (fListeners.isEmpty() && fProblemChangedListener != null)
  			{
  				VdmUIPlugin.getDefault()
  						.getProblemMarkerManager()
  						.removeListener(fProblemChangedListener);
  				fProblemChangedListener = null;
  			}
  		}
  	}
docs: /*
  (non-Javadoc)
  
  @see IBaseLabelProvider#removeListener(ILabelProviderListener)