public void exampleDataCollectionGroup()

in firestore/app/src/main/java/com/google/example/firestore/DocSnippets.java [952:1006]
43 lines of code
1 McCabe index (conditional complexity)

    public void exampleDataCollectionGroup() {
        // [START fs_collection_group_query_data_setup]
        CollectionReference citiesRef = db.collection("cities");

        Map<String, Object> ggbData = new HashMap<>();
        ggbData.put("name", "Golden Gate Bridge");
        ggbData.put("type", "bridge");
        citiesRef.document("SF").collection("landmarks").add(ggbData);

        Map<String, Object> lohData = new HashMap<>();
        lohData.put("name", "Legion of Honor");
        lohData.put("type", "museum");
        citiesRef.document("SF").collection("landmarks").add(lohData);

        Map<String, Object> gpData = new HashMap<>();
        gpData.put("name", "Griffith Park");
        gpData.put("type", "park");
        citiesRef.document("LA").collection("landmarks").add(gpData);

        Map<String, Object> tgData = new HashMap<>();
        tgData.put("name", "The Getty");
        tgData.put("type", "museum");
        citiesRef.document("LA").collection("landmarks").add(tgData);

        Map<String, Object> lmData = new HashMap<>();
        lmData.put("name", "Lincoln Memorial");
        lmData.put("type", "memorial");
        citiesRef.document("DC").collection("landmarks").add(lmData);

        Map<String, Object> nasaData = new HashMap<>();
        nasaData.put("name", "National Air and Space Museum");
        nasaData.put("type", "museum");
        citiesRef.document("DC").collection("landmarks").add(nasaData);

        Map<String, Object> upData = new HashMap<>();
        upData.put("name", "Ueno Park");
        upData.put("type", "park");
        citiesRef.document("TOK").collection("landmarks").add(upData);

        Map<String, Object> nmData = new HashMap<>();
        nmData.put("name", "National Museum of Nature and Science");
        nmData.put("type", "museum");
        citiesRef.document("TOK").collection("landmarks").add(nmData);

        Map<String, Object> jpData = new HashMap<>();
        jpData.put("name", "Jingshan Park");
        jpData.put("type", "park");
        citiesRef.document("BJ").collection("landmarks").add(jpData);

        Map<String, Object> baoData = new HashMap<>();
        baoData.put("name", "Beijing Ancient Observatory");
        baoData.put("type", "museum");
        citiesRef.document("BJ").collection("landmarks").add(baoData);
        // [END fs_collection_group_query_data_setup]
    }