I'm adding an expression to a requirement customisation, which I am writing in Jython. I can read the arg1 parameter and I can get the basic details of the requirement that is calling into the script, e.g.

arg1.getHumanName()

arg1.getQualifiedName()

arg1.getName()

arg1.ID

However I cannot figure out how to get at the more specific properties of the requirement (those that you see in the specification). For example I cannot get at the requirement Id by writing,

arg1.getId() 

or the comments text by writing,

arg1.getComments()

I'm sure I'm missing something, if anyone can help I would be most grateful!