from odoo import api, fields, models, _


class ResUsers(models.Model):
    _inherit = 'res.users'

    def _default_groups_custom(self):
        """
        Prevents newly created user from holding all managers groups.
        """
        default_user = self.env.ref('base.group_user', raise_if_not_found=False)
        return default_user

    groups_id = fields.Many2many(
        'res.groups', 'res_groups_users_rel', 'uid', 'gid',
        string='Groups', default=_default_groups_custom
    )