code: protected Collection<Pattern> createPatternForMappedAttribute(final String attributeName) {
          val matchingPattern = patterns.get(attributeName).toString();
          val pattern = RegexUtils.createPattern(matchingPattern, this.caseInsensitive ? Pattern.CASE_INSENSITIVE : 0);
          LOGGER.debug("Created pattern for mapped attribute filter [{}]", pattern.pattern());
          return CollectionUtils.wrap(pattern);
      }
docs: Create pattern for mapped attribute pattern.
  
  @param attributeName the attribute name
  @return the pattern