Gets or sets the HTML template for the page header.

This should be a valid HTML markup that may include the following special classes used to inject print values:

• 'date'formatted print date
• 'title'document title
• 'url'document location
• 'pageNumber'current page number
• 'totalPages'total pages in the document

For example, "<span class='title'></span>" would generate a span containing the document title.