code: def test_flattening_with_sdf_load_notask():
      cur_dir = os.path.dirname(os.path.realpath(__file__))
      featurizer = dc.feat.ConvMolFeaturizer(
          per_atom_fragmentation=True
      )
      loader = dc.data.SDFLoader(
          [], featurizer=featurizer, sanitize=True
      )
      dataset = loader.create_dataset(
          os.path.join(cur_dir, "membrane_permeability.sdf")
      )
      transformer = dc.trans.FlatteningTransformer(dataset=dataset)
      frag_dataset = transformer.transform(dataset)
      assert len(frag_dataset) == 98
  
file_path: deepchem/deepchem/trans/tests/test_flattening.py
imports: import tempfile
  import os
  import deepchem
  import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: test_flattening_with_sdf_load_notask() without return types