FT Digital Edition: our digitised print edition
return PI * (radius ** 2.0);
，推荐阅读新收录的资料获取更多信息
"spatial": {"object_position": [1.3, 0.7, 0.42], "target_position": [1.25, 0.6, 0.42]},
#[derive(Debug, Clone, thiserror::Error)]
DisplayManager& operator=(const DisplayManager&) = default;