code: private void getOperators(List<ExampleQuery> exQueries, String regex)
    {
  
      Pattern opsRegex = Pattern.compile(regex);
      for (ExampleQuery eQ : exQueries)
      {
        List<String> ops = new ArrayList<>();
        Matcher m = opsRegex.matcher(eQ.getExampleQuery().replaceAll("\\s", ""));
  
        while (m.find())
        {
          ops.add(m.group());
        }
  
        eQ.setUsedOperators("{" + StringUtils.join(ops, ",") + "}");
      }
    }
docs: Fetches operators used in the {@link ExampleQuery#getExampleQuery()} with a
  given regex.
  
  @param exQueries Set the used operators property of each member.
  @param regex The regex to search operators.