ThreatDescription td = threat_model.getThreatDescription();
    public void handleThreatModelChange( ThreatModelChangeEvent tm_change )            throws BelievabilityException    {        // We just relay this to the specific state dimension model,        // as that is where the data structures for this are managed.        //                if ( tm_change == null )            throw new BelievabilityException                    ( "AssetTypeModel.handleThreatModelChange()",                      "Found NULL for threat change object." );                ThreatModelInterface threat_model = tm_change.getThreatModel();                ThreatDescription td = threat_model.getThreatDescription();                if ((threat_model == null )            || ( threat_model.getThreatDescription() == null )            || ( threat_model.getThreatDescription                 ().getEventThreatCauses() == null ))            throw new BelievabilityException                    ( "AssetTypeModel.handleThreatModelChange()",                      "Found NULL while trying to retrieve state dimension." );        EventDescription ed                = threat_model.getThreatDescription().getEventThreatCauses();                String state_dim_name = ed.getAffectedStateDimensionName();                int dim_idx = getStateDimIndex( state_dim_name );        if (( dim_idx < 0 ) || ( dim_idx >= _dim_model.length ))            throw new BelievabilityException                    ( "AssetTypeModel.handleThreatModelChange()",                      "Threat has unknown state dimension : "                      + state_dim_name );                _dim_model[dim_idx].handleThreatModelChange( tm_change );    } // method handleThreatModelChange