code: def test_vectorize(self):
      size = 16
      feature_dict = {0: "C", 1: "CC", 2: "CCC"}
      hash_function = hash_utils.hash_ecfp
      vector = hash_utils.vectorize(hash_function, feature_dict, size)
      assert vector.shape == (size,)
      assert np.count_nonzero(vector) == len(feature_dict)
  
file_path: deepchem/deepchem/utils/test/test_hash_utils.py
imports: import unittest
  import numpy
  from deepchem.utils import hash_utils
label_desc: Use image node_id 3 for calling the TestHashUtils obj's underlying member method code with example usage: obj.test_vectorize() without return types