code: function _leftShift(buffer) {
          var carry;
          for (var i = buffer.length; i >= 0; i--) {
              carry = (buffer[i] & 0x80) !== 0;
              buffer[i] = (buffer[i] << 1) & 0xFF;
              if (carry && i >= 0) {
                  buffer[i + 1] |= 0x01;
              }
          }
      }
docs: /*
  Performs buffer left bits shift