AddTaskGroup.
        [Preview API] Create a task group.
        :param :class:`<TaskGroupCreateParameter> <azure.devops.v5_0.task_agent.models.TaskGroupCreateParameter>` task_group: Task group object to create.
        :param str project: Project ID or project name
        :rtype: :class:`<TaskGroup> <azure.devops.v5_0.task_agent.models.TaskGroup>`

def add_task_group(self, task_group, project):
        """AddTaskGroup.
        [Preview API] Create a task group.
        :param :class:`<TaskGroupCreateParameter> <azure.devops.v5_0.task_agent.models.TaskGroupCreateParameter>` task_group: Task group object to create.
        :param str project: Project ID or project name
        :rtype: :class:`<TaskGroup> <azure.devops.v5_0.task_agent.models.TaskGroup>`
        """
        route_values = {}
        if project is not None:
            route_values['project'] = self._serialize.url('project', project, 'str')
        content = self._serialize.body(task_group, 'TaskGroupCreateParameter')
        response = self._send(http_method='POST',
                              location_id='6c08ffbf-dbf1-4f9a-94e5-a1cbd47005e7',
                              version='5.0-preview.1',
                              route_values=route_values,
                              content=content)
        return self._deserialize('TaskGroup', response)