class_docstr: Test the functionality of tabix.build_index.
class_docstr_tok: ["Test","the","functionality","of","tabix.build_index","."]
code: def test_build_index_tbx(self):
      self.assertFalse(epath.Path(self.tbx_index_file).exists())
      tabix.build_index(self.output_file)
      self.assertTrue(epath.Path(self.tbx_index_file).exists())
  
file_path: deepvariant/third_party/nucleus/io/tabix_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import shutil
  from absl.testing import absltest
  from etils import epath
  from third_party.nucleus.io import tabix
  from third_party.nucleus.io import vcf
  from third_party.nucleus.testing import test_utils
  from third_party.nucleus.util import ranges
label_desc: Use image node_id 3 for calling the TabixTest obj's underlying member method code with example usage: obj.test_build_index_tbx() without return types