code: def test_helper_functions():
      """
      Test for get_atomic_num_one_hot(), get_atom_chiral_tag_one_hot() and get_atom_mass() helper functions
      """
      smiles = "C"
      m = Chem.MolFromSmiles(smiles)
      atom = m.GetAtoms()[0]
      f_atomic = get_atomic_num_one_hot(
          atom, GraphConvConstants.ATOM_FEATURES["atomic_num"]
      )
      req_f = list(np.zeros((101,), dtype=float))
      req_f[5] = 1.0
      assert len(f_atomic) == len(req_f)
      assert f_atomic == req_f
  
      f_chiral_tag = get_atom_chiral_tag_one_hot(
          atom, GraphConvConstants.ATOM_FEATURES["chiral_tag"]
      )
      ref_f = [1.0, 0.0, 0.0, 0.0, 0.0]
      assert len(f_chiral_tag) == len(ref_f)
      assert f_chiral_tag == ref_f
  
      f_mass = get_atom_mass(atom)
      ref_f = [0.12011]
      assert len(f_mass) == len(ref_f)
      assert f_mass == ref_f
  
file_path: deepchem/deepchem/feat/tests/test_atom_feature_generator_dmpnn.py
imports: from deepchem.feat.molecule_featurizers.dmpnn_featurizer import get_atomic_num_one_hot, get_atom_chiral_tag_one_hot, get_atom_mass, atom_features, GraphConvConstants
  from rdkit import Chem
  import pytest
  import numpy
label_desc: Use image node_id 2 for calling a global function with example usage: test_helper_functions() without return types