public virtual void FlushObjStm()
{
if (numObj == 0)
return;
int first = index.Size;
index.Append(streamObjects);
PdfStream stream = new PdfStream(index.ToByteArray());
stream.FlateCompress(writer.CompressionLevel);
stream.Put(PdfName.TYPE, PdfName.OBJSTM);
stream.Put(PdfName.N, new PdfNumber(numObj));
stream.Put(PdfName.FIRST, new PdfNumber(first));
Add(stream, currentObjNum);
index = null;
streamObjects = null;
numObj = 0;
}