@Override
    public Result search(Query query, Execution execution) {
        try {
            checkQuery(query);
        } catch (IllegalInputException e) {
            log.log(Level.FINE, () -> "Rejected query '" + query.toString() + "' on cause of: " + Exceptions.toMessageString(e));
            return new Result(query, ErrorMessage.createIllegalQuery(e.getMessage()));
        }
        return execution.search(query);
    }
Check whether the query tree seems to be "well formed". In other words, run heuristics against
the input data to see whether the query should sent to the search backend.

@author Steinar Knutsen
container-search/src/main/java/com/yahoo/search/searchers/InputCheckingSearcher.java