How should I get path or remoteUrl of ArtifactInfo?

Hi, I am try to use Maven-Indexer to search artifacts from Nexus3. But I get some problems.
I cannot get path or remoteUrl of ArtifactInfo, It always be null.
My code refers to maven-indexer/ at master · apache/maven-indexer · GitHub.

    public void listJenkinsPlugins() throws IOException {
        // Case:
        // Use index
        // Searching for some artifact
        Query hpiQ =
                indexer.constructQuery(MAVEN.PACKAGING, new SourcedSearchExpression("hpi"));

        BooleanQuery bq = new BooleanQuery();
        bq.add( hpiQ, Occur.MUST );
        System.out.println( "Searching for jenkins plugins " );
        FlatSearchResponse response = indexer.searchFlat(new FlatSearchRequest(hpiQ, centralContext));
        for (ArtifactInfo ai : response.getResults()) {
           // it always be null
            System.out.println(ai.getPath()+ ":  " + ai.toString());
           System.out.println(ai.getRemoteUrl()+ ":  " + ai.toString());

Any help will be appreciated.

Anyone could share some informations ?

I suspect maven-idnex relies on the old lucene index which we do not generate in nxrm3.