text: from ..common.optim import SGD as optimizer
  from ..common.coco_schedule import lr_multiplier_1x as lr_multiplier
  from ..common.data.coco import dataloader
  from ..common.models.mask_rcnn_fpn import model
  from ..common.train import train
  
  model.backbone.bottom_up.freeze_at = 2
  train.init_checkpoint = "detectron2://ImageNetPretrained/MSRA/R-50.pkl"
  