code: private static String osString()
      {
          OSType osType = calculateOS();
          return osType.toString().toLowerCase(Locale.ENGLISH);
      }
docs: Returns a the <strong>lower case</strong> String representation of
  the {@link #calculateOS() OSType} of this platform. E.g.
  <code>"windows"</code>.
  
  @return The string describing the operating system