code: public Configuration withMatcher(String matcherName, Matcher<?> matcher) {
          return new Configuration(tolerance, options, ignorePlaceholder, matchers.with(matcherName, matcher), pathsToBeIgnored, differenceListener);
      }
docs: Adds a matcher to be used in ${json-unit.matches:matcherName} macro.
  
  @param matcherName
  @param matcher
  @return