question: public void addPlotConfigChangeEvent ( PlotConfiguration newSource , PlotConfigurationChangeEvent changeEvent ) { if ( type != PlotConfigurationChangeType . META_CHANGE ) { throw new IllegalArgumentException ( "Wrong type. Only META_CHANGE is allowed!" ) ; } source = newSource ; plotConfigChangeEvents . add ( changeEvent ) ; }
target:  This function can only be called if type of change event is META_CHANGE