* @return the Response as JSON String
* @throws IOException
*/
protected String restSQLExecute(String source, boolean includeTypes) throws IOException {
XContentBuilder builder = XContentFactory.contentBuilder(XContentType.JSON);
builder.generator().usePrettyPrint();
SQLXContentSourceContext context = new SQLXContentSourceContext();
SQLXContentSourceParser parser = new SQLXContentSourceParser(context);
parser.parseSource(new BytesArray(source));
SQLBaseResponse sqlResponse;