    # File lib/standard/facets/random.rb, line 353
          def random(max_length = 8, char_re = /[\w\d]/)
            raise ArgumentError.new('char_re must be a regular expression!') unless char_re.is_a?(Regexp)
            string = ""
            while string.length < max_length
                ch = Random.number(255).chr
                string << ch if ch =~ char_re
            end
            return string
          end