How to change a space between lines in PurePDF?

I want to change a s开发者_StackOverflow社区pace between lines in document with PurePDF but i cannot find a way to do it. I used Chunk and Paragraph for output text but they haven't any properties to change space between lines. Please help.

\n will do. For example

        var title:Paragraph = new Paragraph("Purchase Order Summary\n\n");          
        title.alignment = Element.ALIGN_CENTER;
        document.add(title);