Hi Richard, thank you for pointing this out, that method is not supposed to be available on linux, we will correct that for the next release.
There is no linux standard way to print, though there are some popular mechanisms (such as CUPS).
Some linux distros even use PDF as the print spool format.
You can also use PDFDraw class to raster PDF pages, and send those to the printer, if you are having issues printing the PDF itself.
I'm not sure exactly what is available on your Fedora distro, but installing CUPS and printing a PDF with that should be straight forward.https://www.cups.org/documentation.php/doc-1.7/api-cups.html#PRINT_JOBS