presto-geospatial-toolkit/src/main/java/io/prestosql/geospatial/KdbTreeUtils.java/KdbTreeUtils/toJson
class KdbTreeUtils:    public static String toJson(KdbTree kdbTree)
    {
        requireNonNull(kdbTree, "kdbTree is null");
        return KDB_TREE_CODEC.toJson(kdbTree);
    }