Config translation from maskrcnn_benchmark

[cinjon]

Hi. Apologies if these questions aren't appreciated due to the elapsed time since the transition from maskrcnn_benchmark.

I have a config from there that I'm trying to translate into detectron2. I understand that not everything will correspond to the detectron2 setup, however I'm wondering if there is a correspondence for any of the following as they appear to be key for the model I'm using:

1. ROI_BOX_HEAD.FEATURE_EXTRACTOR: "FPN2MLPFeatureExtractor"
2. ROI_BOX_HEAD.PREDICTOR: "FPNPredictor"
3. ROI_BOX_HEAD.POOLER_SCALES: (0.25, 0.125, 0.0625, 0.03125)

Thanks.