code: def load_meta(self, root_dir, dataset: Input):
      meta_file = join(root_dir, "meta.yaml")
      if not exists(meta_file):
          raise ValueError(
              f"The {root_dir} should contain a `meta.yaml` file about the classes."
          )
  
      with open(meta_file) as f:
          self.meta = yaml.safe_load(f)
  
      if "label_to_names" not in self.meta:
          raise ValueError(
              f"The {root_dir} should contain a `meta.yaml` file about the classes with the field `label_to_names`."
          )
  
      dataset.num_classes = len(self.meta["label_to_names"])
      dataset.label_to_names = self.meta["label_to_names"]
      dataset.color_map = self.meta["color_map"]
  
imports: import os
  from os.path import basename, dirname, exists, isdir, isfile, join
  from typing import Any, Dict, List, Optional, Type, Union
  import yaml
  from flash.core.data.io.input import BaseDataFormat, Input
  from flash.core.utilities.imports import _TOPIC_POINTCLOUD_AVAILABLE
label_desc: Use image node_id 2 for calling the KITTIPointCloudObjectDetectorLoader obj's underlying member method code with example usage: obj.load_meta(root_dir, dataset) without return types