docstr: Number of scales in the multiscale array
          
docstr_tok: ["Number","of","scales","in","the","multiscale","array"]
code: def num_scales(self):
      """Number of scales in the multiscale array"""
      return (
          len(self.multiscale)
          if hasattr(self, "multiscale") and self.multiscale
          else 0
      )
  
file_path: torch-points3d/torch_points3d/datasets/multiscale_data.py
imports: from typing import List, Optional
  import torch
  import copy
  import torch_geometric
  from torch_geometric.data import Data
  from torch_geometric.data import Batch
label_desc: Use image node_id 3 for calling the MultiScaleData obj's underlying member method code with example usage: obj.num_scales() and returns: unknown