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);
    }
Create pattern for mapped attribute pattern.

@param attributeName the attribute name
@return the pattern
core/cas-server-core-services-api/src/main/java/org/apereo/cas/services/support/RegisteredServiceMappedRegexAttributeFilter.java