code: public void updateImpliedStores( @Observes final ArtifactStorePreUpdateEvent event )
      {
          if ( !storeManager.isStarted() )
          {
              return;
          }
  
          if ( !config.isEnabled() )
          {
              logger.debug( "Implied-repository processing is not enabled." );
              return;
          }
  
          try
          {
              // TODO: Update for changes map.
              final Map<StoreKey, ArtifactStore> currentStores = mapStores( event );
  
              for ( final ArtifactStore store : event )
              {
                  logger.debug( "Processing store: {} for implied repo metadata", store );
                  processStore( store, currentStores );
              }
          }
          catch ( Throwable error )
          {
              Logger logger = LoggerFactory.getLogger( getClass() );
              logger.error( String.format( "Implied-repository maintenance failed: %s", error.getMessage() ), error );
          }
      }
docs: We cannot currently remove formerly implied repos because we can't distinguish between the above states.