class_docstr: Helper to visualize the clusters assignment of images
  
  This class is meant to be used in a notebook and will generate
  visualisations for the different clusters
class_docstr_tok: ["Helper","to","visualize","the","clusters","assignment","of","images","This","class","is","meant","to","be","used","in","a","notebook","and","will","generate","visualisations","for","the","different","clusters"]
code: def _to_cluster_to_image_map(
      cluster_assignments: Dict[int, int]
  ) -> Dict[int, List[int]]:
      cluster_to_images = {}
      for image_id, cluster_id in cluster_assignments.items():
          cluster_to_images.setdefault(cluster_id, []).append(image_id)
      return cluster_to_images
  
file_path: vissl/vissl/utils/cluster_utils.py
imports: import os
  from dataclasses import dataclass
  from typing import Dict, List
  import numpy
  import torch
  from iopath.common.file_io import g_pathmgr
  from vissl.config import AttrDict
  from vissl.data import build_dataset
label_desc: Use image node_id 4 for calling the ClusterVisualizer obj's underlying member method code with example usage: obj._to_cluster_to_image_map(cluster_assignments) and returns: cluster_to_images