code: def test_gfile_isdir(remote_filename):
      """Test case for isdir()"""
  
      # A valid http link is not a dir.
      assert not tf.io.gfile.isdir(remote_filename)
      # An invalid http link is not a dir either.
      assert not tf.io.gfile.isdir(
          "https://not-a-valid-domain/tfio-test"
      )
  
file_path: io/tests/test_http.py
imports: import os
  import sys
  import pytest
  import tensorflow
  import tensorflow_io
label_desc: Use image node_id 9 for calling a global function with example usage: test_gfile_isdir(remote_filename) without return types