code: def setUp(self):
      current_dir = os.path.dirname(os.path.realpath(__file__))
  
      # simple flat ring
      from rdkit.Chem import MolFromSmiles
      from rdkit.Chem.rdDepictor import Compute2DCoords
  
      self.cycle4 = MolFromSmiles("C1CCC1")
      # self.cycle4.Compute2DCoords()
      Compute2DCoords(self.cycle4)
  
      # load and sanitize two real molecules
      _, self.prot = load_molecule(
          os.path.join(
              current_dir,
              "../../feat/tests/data/3ws9_protein_fixer_rdkit.pdb",
          ),
          add_hydrogens=False,
          calc_charges=False,
          sanitize=True,
      )
  
      _, self.lig = load_molecule(
          os.path.join(
              current_dir, "../../feat//tests/data/3ws9_ligand.sdf"
          ),
          add_hydrogens=False,
          calc_charges=False,
          sanitize=True,
      )
  
imports: import os
  import unittest
  import numpy
  from deepchem.utils.rdkit_utils import load_molecule
  from deepchem.utils.rdkit_utils import compute_ring_center
  from deepchem.utils.rdkit_utils import compute_ring_normal
  from deepchem.utils.noncovalent_utils import is_pi_parallel
  from deepchem.utils.noncovalent_utils import is_pi_t
  from deepchem.utils.noncovalent_utils import compute_pi_stack
  from deepchem.utils.noncovalent_utils import is_cation_pi
  from deepchem.utils.noncovalent_utils import compute_cation_pi
  from deepchem.utils.noncovalent_utils import compute_binding_pocket_cation_pi
label_desc: Use image node_id 1 for calling the TestPiInteractions obj's underlying member method code with example usage: obj.setUp() without return types