docs: def xform(self, left, right, repeating, base, sign):
          """
          Return prefixes for tuple.
  
          :param str left: left of the radix
          :param str right: right of the radix
          :param str repeating: repeating part
          :param int base: the base in which value is displayed
          :param int sign: -1, 0, 1 as appropriate
          :returns: the number string
          :rtype: str
          """
          # pylint: disable=too-many-arguments
  
          base_prefix = ''
          if self.CONFIG.use_prefix:
              if base == 8:
                  base_prefix = '0'
              elif base == 16:
                  base_prefix = '0x'
              else:
                  base_prefix = ''
  
          base_subscript = str(base) if self.CONFIG.use_subscript else ''
  
          result = {
             'sign' : '-' if sign == -1 else '',
             'base_prefix' : base_prefix,
             'left' : left,
             'radix' : '.' if (right != "" or repeating != "") else "",
             'right' : right,
             'repeating' : ("(%s)" % repeating) if repeating != "" else "",
             'base_separator' : '' if base_subscript == '' else '_',
             'base_subscript' : base_subscript
          }
  
          return self._FMT_STR % result