docs: protected ArtifactStore createArtifactStore()
          throws MojoExecutionException
      {
          if ( repositories == null )
          {
              getLog().info( "Configuring Mock Repository Manager to proxy through this Maven instance" );
              return createProxyArtifactStore();
          }
          getLog().info( "Configuring Mock Repository Manager..." );
          List<ArtifactStore> stores = new ArrayList<ArtifactStore>();
          if ( repositories == null || repositories.length == 0 )
          {
              repositories = new ArtifactStoreFactory[]{ new ProxyRepo() };
          }
          FactoryHelper helper = createFactoryHelper();
          for ( ArtifactStoreFactory artifactStoreFactory : repositories )
          {
              if ( artifactStoreFactory instanceof FactoryHelperRequired )
              {
                  ( (FactoryHelperRequired) artifactStoreFactory ).setFactoryHelper( helper );
              }
              getLog().info( "  " + artifactStoreFactory.toString() );
              stores.add( artifactStoreFactory.newInstance() );
          }
          ArtifactStore[] artifactStores = (ArtifactStore[]) stores.toArray( new ArtifactStore[stores.size()] );
          return artifactStores.length == 1 ? artifactStores[0] : new CompositeArtifactStore( artifactStores );
      }