'Evaluate the ir.actions.server action specified in the activity.'

def wkf_expr_execute_action(self, activity):

    context = {'active_model': self.record.model, 'active_id': self.record.id, 'active_ids': [self.record.id]}
    env = odoo.api.Environment(self.session.cr, self.session.uid, context)
    action = env['ir.actions.server'].browse(activity['action_id'])
    result = action.run()
    return result
