*/
public static MetadataQuerySearch parseQuery(String queryString) throws Exception {
CharStream charStream = new ANTLRStringStream(queryString);
QueryLexer exprLexer = new QueryLexer(charStream);
TokenStream tokenStream = new CommonTokenStream(exprLexer);
QueryParser parser = new QueryParser(tokenStream);
QueryParser.expression_return tree = parser.expression();
return new MetadataQuerySearch((CommonTree)tree.getTree());
}