code: def _len(x):
      if _is_sparse(x):
          return x.shape[0]
      return len(x)
  
imports: import warnings
  from collections.abc import Mapping
  from functools import partial
  from numbers import Number
  import numpy
  from scipy import sparse
  from sklearn.model_selection import ShuffleSplit
  from sklearn.model_selection import StratifiedKFold
  from sklearn.model_selection import StratifiedShuffleSplit
  from sklearn.model_selection import check_cv
  import torch
  import torch.utils.data
  from skorch.utils import flatten
  from skorch.utils import is_pandas_ndframe
  from skorch.utils import check_indexing
  from skorch.utils import multi_indexing
  from skorch.utils import to_numpy
label_desc: Use image node_id 3 for calling a global function with example usage: _len(x) and returns: len, x