public static void queryHashes()

in firestore/app/src/main/java/com/google/example/firestore/SolutionGeoqueries.java [51:99]
32 lines of code
5 McCabe index (conditional complexity)

    public static void queryHashes() {
        // [START fs_geo_query_hashes]
        // Find cities within 50km of London
        final GeoLocation center = new GeoLocation(51.5074, 0.1278);
        final double radiusInM = 50 * 1000;

        // Each item in 'bounds' represents a startAt/endAt pair. We have to issue
        // a separate query for each pair. There can be up to 9 pairs of bounds
        // depending on overlap, but in most cases there are 4.
        List<GeoQueryBounds> bounds = GeoFireUtils.getGeoHashQueryBounds(center, radiusInM);
        final List<Task<QuerySnapshot>> tasks = new ArrayList<>();
        for (GeoQueryBounds b : bounds) {
            Query q = db.collection("cities")
                    .orderBy("geohash")
                    .startAt(b.startHash)
                    .endAt(b.endHash);

            tasks.add(q.get());
        }

        // Collect all the query results together into a single list
        Tasks.whenAllComplete(tasks)
                .addOnCompleteListener(new OnCompleteListener<List<Task<?>>>() {
                    @Override
                    public void onComplete(@NonNull Task<List<Task<?>>> t) {
                        List<DocumentSnapshot> matchingDocs = new ArrayList<>();

                        for (Task<QuerySnapshot> task : tasks) {
                            QuerySnapshot snap = task.getResult();
                            for (DocumentSnapshot doc : snap.getDocuments()) {
                                double lat = doc.getDouble("lat");
                                double lng = doc.getDouble("lng");

                                // We have to filter out a few false positives due to GeoHash
                                // accuracy, but most will match
                                GeoLocation docLocation = new GeoLocation(lat, lng);
                                double distanceInM = GeoFireUtils.getDistanceBetween(docLocation, center);
                                if (distanceInM <= radiusInM) {
                                    matchingDocs.add(doc);
                                }
                            }
                        }

                        // matchingDocs contains the results
                        // ...
                    }
                });
        // [END fs_geo_query_hashes]
    }