presto-elasticsearch/src/main/java/io/prestosql/elasticsearch/ElasticsearchColumn.java/ElasticsearchColumn/toString
class ElasticsearchColumn:    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("name", name)
                .add("type", type)
                .add("jsonPath", jsonPath)
                .add("ordinalPosition", ordinalPosition)
                .toString();
    }