old_contents: class NumberToWords(object):
      """
      Class for converting positive integer values to a textual representation
      of the submitted number for value of 0 up to 999999999.
      """
  
      MAX = 999999999
      SMALL_NUMBERS = ['', 'one', 'two', 'three', 'four', 'five', 'six',
                       'seven', 'eight', 'nine', 'ten', 'eleven',
                       'twelve', 'thirteen', 'fourteen', 'fifteen', 'sixteen',
                       'seventeen', 'eighteen', 'nineteen']
      TENS = ['', '', 'twenty', 'thirty', 'fourty', 'fifty', 'sixty', 'seventy',
              'eighty', 'ninety']
      LARGE_NUMBERS = ['', 'thousand', 'million']
      EXCEPTION_STRING = "This method expects positive integer values between " \
          + "0 and {0}".format(MAX)
  
      def convert(self, number):
          """
          Take an integer and return it converted to a textual representation.
  
          Args:
              number (int): The number to be converted.
  
          Returns:
              sentence (string): The textual representation of `number`.
  
          Raises:
              ValueError: If `number` is not a positive integer or is greater
                          than `MAX`.
          """
  
          if not isinstance(number, (int, long)):
              raise ValueError(self.EXCEPTION_STRING)
          sentence = ""
          if number is 0:
              sentence = "zero"
          else:
              # split number into a list of strings where each list item is
              # at most 3 character in length.
              groups = format(number, ',').split(',')
  
              # make sure each list item is exactly 3 characters long by
              # zero filling
              zero_filled_groups = []
              for group in groups:
                  zero_filled_groups.append(group.zfill(3))
  
              # reverse the list of strings so that the list indexes of the
              # string representation of hundreds, thousands and million
              # match those of `LARGE_NUMBERS`
              zero_filled_groups.reverse()
          return sentence.rstrip()
  
new_contents: class NumberToWords(object):
      """
      Class for converting positive integer values to a textual representation
      of the submitted number for value of 0 up to 999999999.
      """
  
      MAX = 999999999
      SMALL_NUMBERS = ['', 'one', 'two', 'three', 'four', 'five', 'six',
                       'seven', 'eight', 'nine', 'ten', 'eleven',
                       'twelve', 'thirteen', 'fourteen', 'fifteen', 'sixteen',
                       'seventeen', 'eighteen', 'nineteen']
      TENS = ['', '', 'twenty', 'thirty', 'fourty', 'fifty', 'sixty', 'seventy',
              'eighty', 'ninety']
      LARGE_NUMBERS = ['', 'thousand', 'million']
      EXCEPTION_STRING = "This method expects positive integer values between " \
          + "0 and {0}".format(MAX)
  
      def convert(self, number):
          """
          Take an integer and return it converted to a textual representation.
  
          Args:
              number (int): The number to be converted.
  
          Returns:
              sentence (string): The textual representation of `number`.
  
          Raises:
              ValueError: If `number` is not a positive integer or is greater
                          than `MAX`.
          """
  
          if not isinstance(number, (int, long)):
              raise ValueError(self.EXCEPTION_STRING)
          sentence = ""
          if number is 0:
              sentence = "zero"
          else:
              # split number into a list of strings where each list item is
              # at most 3 character in length.
              groups = format(number, ',').split(',')
  
              # make sure each list item is exactly 3 characters long by
              # zero filling
              zero_filled_groups = []
              for group in groups:
                  zero_filled_groups.append(group.zfill(3))
  
              # reverse the list of strings so that the list indexes of the
              # string representation of hundreds, thousands and million
              # match those of `LARGE_NUMBERS`
              zero_filled_groups.reverse()
          return sentence.rstrip()
  
      def _number_to_word_list(self, number_string, suffix=None):
          """
          Take a 3 digit string representation of an integer and convert it to a
          textual representation with an optional suffix.
          """
  
subject: Create private utility function to turn each 3 digit item into words