*/
    public static void releaseLastXrefPartial(final PdfObject obj) {
        if (obj == null)
            return;
        if (!obj.isIndirect())
            return;
        if (!(obj instanceof PRIndirectReference))
            return;

        PRIndirectReference ref = (PRIndirectReference)obj;
        PdfReader reader = ref.getReader();
        if (reader.partial && reader.lastXrefPartial != -1 && reader.lastXrefPartial == ref.getNumber()) {
            reader.xrefObj.set(reader.lastXrefPartial, null);
        }
        reader.lastXrefPartial = -1;
    }