How to know status of usb modem connection when using NCDEnterprise class in

Just received several iot sensors and modems.
I am testing sensors and wireless USB modem via NCDEnterpise-Python, everything works like a charm. Very impressive.
I am using it in my application and I need to detect when USB modem was disconencted from PC to recreate the instance. Right now, NCDEnterprise instance fails background but my application doesn’t know it.
How to check the status?