code: def on_fit(self, dataset_path):
      self.split = basename(dataset_path)
  
      self.load_meta(dirname(dataset_path))
      self.dataset_path = dataset_path
      self.label_to_names = self.get_label_to_names()
      self.num_classes = len(self.label_to_names) - len(
          self.ignored_label_inds
      )
      self.make_datasets()
  
file_path: lightning-flash/src/flash/pointcloud/segmentation/open3d_ml/sequences_dataset.py
imports: import os
  from os.path import basename, dirname, exists, isdir, isfile, join, split
  import numpy
  import yaml
  from torch.utils.data import Dataset
  from flash.core.utilities.imports import _TOPIC_POINTCLOUD_AVAILABLE
label_desc: Use image node_id 3 for calling the SequencesDataset obj's underlying member method code with example usage: obj.on_fit(dataset_path) without return types