class_docstr: A class to load datasets, evaluate results for a datast split (e.g., "coco_train_2017")
  
  To use your own dataset that's not in COCO format, write a subclass that
  implements the interfaces.
docstr: Returns:
      roidbs (list[dict]):
  
      Each dict corresponds to one image to run inference on. The
      following keys in the dict are expected:
  
      file_name (str): full path to the image
      image_id (str): an id for the image. The inference results will be stored with this id.
code: def inference_roidbs(self):
      """
      Returns:
          roidbs (list[dict]):
  
          Each dict corresponds to one image to run inference on. The
          following keys in the dict are expected:
  
          file_name (str): full path to the image
          image_id (str): an id for the image. The inference results will be stored with this id.
      """
      raise NotImplementedError()
  
file_path: tensorpack/examples/FasterRCNN/dataset/dataset.py
imports: from collections import defaultdict
label_desc: Use image node_id 2 for calling the DatasetSplit obj's underlying member method code with example usage: obj.inference_roidbs() without return types