class_docstr: Base model for object detection or instance segmentation with matching.
  
  This model implements the classification and matching parts which are shared
  between the object detection and instance segmentation models.
code: def build_flax_model(self):
      raise NotImplementedError(
          "Subclasses must implement build_flax_module()."
      )
  
imports: import abc
  import functools
  from typing import Any, Callable, Dict, Optional, Tuple
  import jax
  import jax.numpy
  import ml_collections
  import numpy
  from scenic.model_lib import matchers
  from scenic.model_lib.base_models import base_model
  from scenic.model_lib.base_models import box_utils
  from scenic.model_lib.base_models import model_utils
label_desc: Use image node_id 11 for calling the BaseModelWithMatching obj's underlying member method code with example usage: obj.build_flax_model() without return types