code: def test_filename_only_constructor(self):
      filename = mkstemp()[1]
      self.run_test(
          """
              def filename_only_constructor(filename):
                  open(filename).close()""",
          filename,
          filename_only_constructor=[str],
      )
  
imports: from tempfile import mkstemp
  from pythran.tests import TestEnv
  import unittest
  from pythran.typing import List
label_desc: Use image node_id 4 for calling the TestFile obj's underlying member method code with example usage: obj.test_filename_only_constructor() without return types