code: @Override
      public boolean registerFileExtension(String mimeTypeName, String fileTypeExtension, String application) throws OSException {
          // TODO create mime-info in /usr/share/mime/packages
          // TODO add MIME type to .desktop file
          // not possible due to missing permissions?
          throw new UnsupportedOperationException("Not supported.");
      }
docs: Registers a new file extension.
  
  @param mimeTypeName MIME type of the file extension. Must be atomic, e.g.
  <code>foocorp.fooapp.v1</code>.
  @param fileTypeExtension File extension with leading dot, e.g.
  <code>.bar</code>.
  @param application Path to the application, which should open the new
  file extension.
  @return <code>true</code> if registration was successful,
  <code>false</code> otherwise.
  @throws OSException