datatables pdf output orientation not working

datatables pdf output orientation not working

I have a really big table with columns exceeding 50. So I want to print
into A2 size output But sPdfOrientation and sPdfSize are not working.
//Button configurations
"aButtons" : [{
"sExtends" : "print",
"sButtonText" : "Print Preview",
"sInfo" : "This is a Print info",
"sMessage" : "This is a print preview. Press 'Esc' to
exit !!!",
"sPdfOrientation": "landscape",
"sPdfSize": "A2"
}, {
"sExtends" : "collection",
"sButtonText" : "Save",
"aButtons" : ["csv", "xls", "pdf"]
}]