class_docstr: Base class for YOLOv2 and YOLOv3.
  
  A subclass of this class should have :obj:`extractor`,
  :meth:`forward`, and :meth:`_decode`.
code: def insize(self):
      return self.extractor.insize
  
file_path: chainercv/chainercv/links/model/yolo/yolo_base.py
imports: import chainer
  from chainer.backends import cuda
  from chainercv import transforms
label_desc: Use image node_id 1 for calling the YOLOBase obj's underlying member method code with example usage: obj.insize() and returns: self