code: function zeroPaddingNumber(value, minDigits, maxDigits, buffer) {
          // Optimization for 1, 2 and 4 digit numbers. This should
          // cover most cases of formatting date/time related items.
          // Note: This optimization code assumes that maxDigits is
          // either 2 or Integer.MAX_VALUE (maxIntCount in format()).
          buffer = buffer || [];
          maxDigits = maxDigits || MAX_VALUE;
          if (value >= 0) {
              if (value < 100 && minDigits >= 1 && minDigits <= 2) {
                  if (value < 10 && minDigits === 2) {
                      buffer.push(zeroDigit);
                  }
                  buffer.push(value);
                  return buffer.join('');
              } else if (value >= 1000 && value < 10000) {
                  if (minDigits === 4) {
                      buffer.push(value);
                      return buffer.join('');
                  }
                  if (minDigits === 2 && maxDigits === 2) {
                      return zeroPaddingNumber(value % 100, 2, 2, buffer);
                  }
              }
          }
          buffer.push(value + '');
          return buffer.join('');
      }
docs: TODO zeroDigit localization?? TODO zeroDigit localization??