Python/Bigsuds: change_my_password does not work for guest user

it doesn't look like from the methods descriptions that a guest can change their own password in iControl. Non-guest accounts are working fine with that method to change the password. It is possible to change guest accounts on their behalf without the old password:

b.Management.UserManagement.change_password_2(['guest1'],[{'is_encrypted': 0, 'password': 'letmein99'}])