public PNGSuggestedPaletteEntry[] getSuggestedPalette() {
        if (!suggestedPaletteSet) {
            throw new IllegalStateException(PropertyUtil.getString("PNGEncodeParam17"));
        }
        return (PNGSuggestedPaletteEntry[])(suggestedPalette.clone());
    }
Returns the suggested palette information to be stored with this
image.

<p> If the suggested palette information has not previously
been set, or has been unset, an
<code>IllegalStateException</code> will be thrown.

@throws IllegalStateException if the suggested palette
       information is not set.
plugins/svg-plugin/batik-codec-fix/src/main/java/org/apache/batik/ext/awt/image/codec/png/PNGEncodeParam.java