code: function(encoded) {
        var numbers = this.decodeUnsignedIntegers(encoded);
  
        var numbersLength = numbers.length;
        for (var i = 0; i < numbersLength; ++i) {
          var num = numbers[i];
          numbers[i] = (num & 1) ? ~(num >> 1) : (num >> 1);
        }
  
        return numbers;
      }
docs: APIMethod: decodeSignedIntegers
  Decode a list of signed integers from an encoded string
  
  Parameters:
  encoded - {string} An encoded string.
  
  Returns:
  {Array.<number>} A list of signed integers.