code: protected boolean canBeUTF8(
          String  str)
      {
          for (int i = str.length() - 1; i >= 0; i--)
          {
              if (str.charAt(i) > 0x00ff)
              {
                  return false;
              }
          }
  
          return true;
      }
docs: return true if the passed in String can be represented without
  loss as a UTF8String, false otherwise.