code: function stringToUint8Array(s) {
      var a = new Uint8Array(s.length);
      for(var i = 0, j = s.length; i < j; ++i) {
          a[i] = s.charCodeAt(i);
      }
      return a;
  }
docs: Convert a string to a Uint8Array.
  @param {!string} s string to convert
  @return {UInt8Array} resulting array