Group-estimate does not work on CLI

[gavin-lai]

Good monring,
The group-estimate option does not seem to work anymore, please see below:
C:\Python27\Scripts>clc-cli billing group-estimate --alias CCVA --location CA2 --group GavinTest
/ Reading clc.ini
x Exiting due to error: 'module' object has no attribute 'Group'
Is this normal or it is a bug?
Thanks
Gavin