class_docstr: Image database.
class_docstr_tok: ["Image","database","."]
code: def default_roidb(self):
      raise NotImplementedError
  
imports: import os
  import os.path
  import PIL
  import numpy
  import scipy.sparse
  from builtins import range
  import sys
  from .utils.cython_bbox import bbox_overlaps
label_desc: Use image node_id 11 for calling the imdb obj's underlying member method code with example usage: obj.default_roidb() without return types