I have used following code  but i get traceback : TypeError: read_group() got multiple values for keyword argument 'context

   @api.model
    def read_group(self, domain, fields, groupby, offset=0, limit=None, orderby=False, lazy=True):
        """ Override read_group to always display all states. """
        if groupby and groupby[0] == "state":
            states = self.EVALUATION_STATE
            read_group_all_states = [{
                        '__context': {'group_by': groupby[1:]},
                        '__domain': domain + [('state', '=', state_value)],
                        'state': state_value,
                    } for state_value, state_name in states]
            read_group_res = super(hr_evaluation, self).read_group(domain, fields, groupby, offset, limit, orderby, lazy)
            result = []
            for state_value, state_name in states:
                res = filter(lambda x: x['state'] == state_value, read_group_res)
                if not res:
                    res = filter(lambda x: x['state'] == state_value, read_group_all_states)
                result.append(res[0])
            return result
        else:
            return super(hr_evaluation, self).read_group(domain, fields, groupby, offset=offset, limit=limit, orderby=orderby, lazy=lazy)

it works well with old api