Elevation Marker, IsReference

I am having trouble accessing the IsReference property of elevation markers using python. I understand how methods work, but i’m still not clear on properties within python. I’ve tried selection.IsReference , but that just says that the object has no attribute called ‘IsReference’
I think that I need to use get attribute, but I can’t figure out the proper syntax.
First, whether to use getattr() or getattribute()
Also, i know that it takes two inputs, the second of which seems like it should be “IsReference”, but I can’t figure out what the first should be.

If someone could show me how to make this work or point me towards some information on how to work with python properties, I’d really appreciate it.

The ultimate goal with this is to make a python node for distinguishing between live and reference elevations and sections