code: def test_InvalidFile(self):
      tmpfile = invalid_textfile(self.tmpdir)
      assert_equal(self.ds.exists(tmpfile), False)
  
imports: import os
  import pytest
  from tempfile import mkdtemp, mkstemp, NamedTemporaryFile
  from shutil import rmtree
  import numpy.lib._datasource
  from numpy.testing import assert_, assert_equal, assert_raises
  import urllib.request
  from urllib.parse import urlparse
  from urllib.error import URLError
label_desc: Use image node_id 6 for calling the TestDataSourceExists obj's underlying member method code with example usage: obj.test_InvalidFile() without return types