code: public ColorModel getColorModel() throws ImageConversionException {
          doFetch(true);
          return buffered != null ? buffered.getColorModel() : colorModel;
      }
docs: Returns the {@code ColorModel} extracted from the
  given {@code ImageSource}. Multiple requests will return the same model.
  
  @return the {@code ColorModel}
  
  @throws ImageConversionException if the given {@code ImageSource} cannot
  be converted for some reason.