docs: protected String removeUnusedPredicates( String expression ) {
          assert expression != null;
          java.util.regex.Matcher matcher = UNUSABLE_PREDICATE_PATTERN.matcher(expression);
          // CHECKSTYLE IGNORE check FOR NEXT 1 LINES
          StringBuffer sb = new StringBuffer();
          if (matcher.find()) {
              do {
                  // Remove those predicates that show up in group 1 ...
                  String predicateStr = matcher.group(0);
                  String unusablePredicateStr = matcher.group(1);
                  if (unusablePredicateStr != null) {
                      predicateStr = "";
                  }
                  matcher.appendReplacement(sb, predicateStr);
              } while (matcher.find());
              matcher.appendTail(sb);
              expression = sb.toString();
          }
          return expression;
      }