[Zope] Adding Role Programmatically

[Samir Mishra]

Hello all,

This is probably simple, but I'm unable to find anything on it.

I'm trying to add a new role to a new folder using a Python script, and am
using -
    context.manage_addFolder(fldr, folders[fldr], 1, 1) # folders is a
dictionary
    # create a new folder named 'fldr' 
    newFolder = getattr(context, fldr)
    # create reviewer role in folder
    newFolder.manage_addRole('Reviewer')

The last line generates the following error -
Line 20: "_addRole" is an invalid attribute name because it starts with "_".

I've looked at the source code in Roles.py but can't find an alternative. 

What should I be doing here? Is there any documentation on this (I can't
find anything in the Zope Book either).

TIA

Samir