Pechkin set content spacing

Pechkin.cs

        public ActionResult PrintForm(string html)
        {
		    var globalConfig = new GlobalConfig();
            globalConfig.SetPaperSize(PaperKind.Letter);
            var margins = new Margins(100, 100, 100, 100);
            globalConfig.SetMargins(margins);           
            var synchronizedPechkin = new SynchronizedPechkin(globalConfig);

            var config = new ObjectConfig();
            config.SetAllowLocalContent(true)                    
                  .SetPrintBackground(true);

            config.Header.SetFont(new Font("Times New Roman", 9F, FontStyle.Underline));
			//The following line has no effect!
            config.Header.SetContentSpacing(20.0);
            config.Header.SetLeftText("Left Header text");
            config.Header.SetRightText("Right Header Text");

            config.Footer.SetFont(new Font("Times New Roman", 12F, FontStyle.Regular));
            config.Footer.SetTexts("Footer text", @"[page] of [topage]", "Right footer text");
            var pdfBuf = synchronizedPechkin.Convert(config, html);            
            
            return File(pdfBuf, "application/pdf", "form.pdf");
}