code: def test_write_gnina_conf(self):
      docking_utils.write_gnina_conf(
          "protein.pdb",
          "ligand.sdf",
          "conf.txt",
      )
      assert os.path.exists("conf.txt")
      os.remove("conf.txt")
  
file_path: deepchem/deepchem/utils/test/test_docking_utils.py
imports: import os
  import numpy
  import unittest
  from deepchem.utils import docking_utils
  from deepchem.utils import rdkit_utils
label_desc: Use image node_id 3 for calling the TestVinaUtils obj's underlying member method code with example usage: obj.test_write_gnina_conf() without return types