code: private FieldSearchQuery assembleFieldSearchQuery(String query, String terms) {
          if (terms != null) {
              return new FieldSearchQuery(terms);
          } else {
              try {
                  return new FieldSearchQuery(Condition.getConditions(query));
              } catch (QueryParseException e) {
                  throw new ValidatorProcessUsageException("Value '" + query
                          + "' of parameter '" + PARAMETER_QUERY
                          + "' is not a valid query string.");
              }
          }
      }
docs: A {@link FieldSearchQuery} may be made from a terms string or a query
  string, but not both.