The specification for the following methods in javax.imageio.ImageWriter needs
to declare various IllegalArgumentExceptions to be thrown:
processWarningOccurred(int imageIndex, String warning);
processWarningOccurred(int imageIndex, String baseName, String keyword);

The declared exceptions should be identical to those declared by the
ImageReader.processWarningOccurred() methods.

Also, the implementation for these methods in ImageWriter needs to be updated
to throw the appropriate exceptions on bad input.