class_docstr: This class is used to create of a subset of a dataset.
  
  Args:
      subset (:class:`torch.utils.data.Dataset`): The given dataset subset.
      transform (function, optional): A transformation applied on each
          sample of the dataset before it will be used. Default is None.
docstr: Returns the number of samples in the subset.
docstr_tok: ["Returns","the","number","of","samples","in","the","subset","."]
code: def __len__(self):
      r"""
      Returns the number of samples in the subset.
      """
      return len(self.subset)
  
imports: import random
  import torch
  import torch.nn.functional
  from torch.utils.data import Dataset
  from torch_geometric.utils import degree
label_desc: Use image node_id 3 for calling the Subset obj's underlying member method code with example usage: obj.__len__() and returns: len