code: function (format) {
              
              _validFormat(format);
              
              var fn = null;
              
              if (_formatFnAll.hasOwnProperty(format))
                  fn = _formatFnAll[format];
              
              else {
                  
                  var m = _regexDecFormat.exec(format);
                  if (m !== null)
                      fn = _getDecFormatter( (  (typeof m[3] === 'string')
                                               ? m[3].length
                                               : 0 ),
                                             (m[1] === '+'),
                                             (m[4] === '%') );
                  else {
                      m = _regexFracFormat.exec(format);
                      if (m !== null)
                          fn = _getFractFormatter( parseInt(m[2], 10),
                                                   (m[1] === '+') );  // isPlus
                  }
                  
                  _formatFnAll[format] = fn;
              }
              
              if (fn !== null)
                  return fn;
              else  // Throw an exception every time
                  throw "IllegalArgumentException: unsupported number format (" + format + ")";
          }
docs: Returns a Function that formats numbers
  into a 'string' value.
  
  Examples:
  Number.getFormatter("0.00")(5.125) == "5.13"
  Number.getFormatter("0.0000")(5.125) == "5.1250"
  Number.getFormatter("0'1/8")(5.125) == "5'1"
  
  @param format {String}
  @return {Function} A function that takes one 'number'
  argument and converts it into a String value.