object detection api: `train_loop` and `checkpoint_max_to_keep`

How are the checkpoint_max_to_keep and checkpoint_every_n options configured in the pipeline configuration files for the object detection api?

I am referring to the parameters to the train_loop function in model_lib_v2.py

Is it as simple as adding these lines as an outermost group in my .config ?

train_loop { checkpoint_max_to_keep=50 checkpoint_every_n=500 }