Double sided prints not working ?

[tanuj101]

conn.printFile(printers[printerID]["name"], path, " ", { "media": "A5", "number-up": "4", "sides": "two-sided-long-edge" })
This is the code to print two sided but it's not working. I'm sure my printer supports two-sided prints this is what I get when I getPrinterAttributes
'sides-supported': ['one-sided', 'two-sided-long-edge', 'two-sided-short-edge']

[tanuj101]

btw the attribute "media" and "number-up" along with several others seem to be working