public synchronized byte[] getPrivateChunkData(int index) {
        return (byte[])chunkData.get(index);
    }
Returns the data associated of the private chunk at a given
index, as an array of <code>byte</code>s.  The index must be
smaller than the return value of
<code>getNumPrivateChunks</code>.
plugins/svg-plugin/batik-codec-fix/src/main/java/org/apache/batik/ext/awt/image/codec/png/PNGEncodeParam.java