# File lib/state_machine/branch.rb, line 174
      def build_matcher(options, whitelist_option, blacklist_option)
        assert_exclusive_keys(options, whitelist_option, blacklist_option)
        
        if options.include?(whitelist_option)
          WhitelistMatcher.new(options[whitelist_option])
        elsif options.include?(blacklist_option)
          BlacklistMatcher.new(options[blacklist_option])
        else
          AllMatcher.instance
        end
      end