logDetail( "Event collection not found for asset '"
if ( _logger.isDetailEnabled() ) _logger.detail( "Event collection not found for asset '"
    EventInstanceCollection getEventInstanceCollection( AssetID asset_id )            throws BelievabilityException    {        // We use lazy evaluation for building the data structure, so        // construct the set if it does not already exist.        EventInstanceCollection event_collection                 = (EventInstanceCollection)                 _asset_event_collection_table.get( asset_id );        // This should evaluate to true and return in the normal case        // where we just return the threat variation set.  We only        // progress past this point if we find that we need to create        // the set (should be the first time we have seen this asset        // ID, or the asset membership in a threat has changed.)        //        if ( event_collection != null )        {            logDetail( "Found existing event collection for asset '"                       + asset_id.getName()                       + "' in dimension '"                       + _state_dim_name );            return event_collection;        }        // Else, we need to construct the set.        logDetail( "Event collection not found for asset '"                   + asset_id.getName()                   + "' in dimension '"                   + _state_dim_name                  + "'. Creating." );        // The constructor here does a fair bit of work in gathering        // applicable stresses into groups of events.  It is this        // EventInstanceCollection data structure that defines the        // stresses applicable to this asset as well as capturing the        // relationships between the stresses (in the case where        // stresses can cause other stresses.)        //        event_collection = new EventInstanceCollection( asset_id,                                                        _stress_set,                                                        this );                // Optionall turn off caching for testing and debugging, or if        // the cache managemrnt turns out to be buggy.        //        if ( USE_EVENT_COLLECTION_CACHING )        {            _asset_event_collection_table.put( asset_id, event_collection );        }        else        {            logDetail( "NOTE: Event collection caching disabled." );        }        return event_collection;    } // method getEventInstanceCollection