It looks like these methods where an alternative to `has_groups`,
but not used since a while.
In Odoo 10.0, there is only one hit, in point_of_sale,
which has been replaced by `user_has_groups`
in 11.0 with revision
34c661111b
In Odoo 9.0, there are a few more hits in base,
which have been replaced by `self.env.user.has_group`
in 11.0 with revision
4ddc323139closesodoo/odoo#111622
Signed-off-by: Xavier Morel (xmo) <xmo@odoo.com>