code: def test_write_pkg_file(self):
      # Check DistributionMetadata handling of Unicode fields
      tmp_dir = self.mkdtemp()
      my_file = os.path.join(tmp_dir, "f")
      klass = Distribution
  
      dist = klass(
          attrs={
              "author": "Mister Café",
              "name": "my.package",
              "maintainer": "Café Junior",
              "description": "Café torréfié",
              "long_description": "Héhéhé",
          }
      )
  
      # let's make sure the file can be written
      # with Unicode fields. they are encoded with
      # PKG_INFO_ENCODING
      dist.metadata.write_pkg_file(open(my_file, "w"))
  
      # regular ascii is of course always usable
      dist = klass(
          attrs={
              "author": "Mister Cafe",
              "name": "my.package",
              "maintainer": "Cafe Junior",
              "description": "Cafe torrefie",
              "long_description": "Hehehe",
          }
      )
  
      my_file2 = os.path.join(tmp_dir, "f2")
      dist.metadata.write_pkg_file(open(my_file2, "w"))
  
imports: import os
  import StringIO
  import sys
  import unittest
  import warnings
  import textwrap
  from distutils.dist import Distribution, fix_help_options
  from distutils.cmd import Command
  import distutils.dist
  from test.test_support import TESTFN, captured_stdout, run_unittest, unlink
  from distutils.tests import support
  from distutils import log
label_desc: Use image node_id 8 for calling the DistributionTestCase obj's underlying member method code with example usage: obj.test_write_pkg_file() without return types