code: def get_post_exclusion_labels(classes):
      """Determines new labels after excluding bad classes.
  
      Excluded classes get the new label -1.
  
      Args:
        classes:  List of tuples containing information about each class.
  
      Returns:
        An array of length num_old_classes, containing new labels.
      """
      old_to_new_labels = np.array(
          [-1 if c.ignore_in_eval else c.train_id for c in classes]
      )
      return old_to_new_labels
  
file_path: scenic/scenic/projects/robust_segvit/datasets/segmentation_datasets.py
imports: import functools
  from typing import Dict, List, Optional, Tuple
  from absl import logging
  import jax.numpy
  import ml_collections
  import numpy
  from scenic.dataset_lib import dataset_utils
  from scenic.dataset_lib import datasets
  from scenic.projects.robust_segvit.datasets import datasets_info
  from scenic.projects.robust_segvit.datasets import denoise_utils
  import tensorflow
label_desc: Use image node_id 3 for calling a global function with example usage: get_post_exclusion_labels(classes) and returns: old_to_new_labels