def METHOD_NAME(self):
    """2to3 a single directory with a new output dir and suffix."""
    self.setup_test_source_trees()
    out = StringIO.StringIO()
    err = StringIO.StringIO()
    suffix = "TEST"
    ret = self.run_2to3_capture(
            ["-n", "--add-suffix", suffix, "--write-unchanged-files",
             "--no-diffs", "--output-dir",
             self.py3_dest_dir, self.py2_src_dir],
            StringIO.StringIO(""), out, err)
    self.assertEqual(ret, 0)
    stderr = err.getvalue()
    self.assertIn(" implies -w.", stderr)
    self.assertIn(
            "Output in %r will mirror the input directory %r layout" % (
                    self.py3_dest_dir, self.py2_src_dir), stderr)
    self.assertEqual(set(name+suffix for name in self.setup_files),
                     set(os.listdir(self.py3_dest_dir)))
    for name in self.setup_files:
        self.assertIn("Writing converted %s to %s" % (
                os.path.join(self.py2_src_dir, name),
                os.path.join(self.py3_dest_dir, name+suffix)), stderr)
    sep = re.escape(os.sep)
    self.assertRegexpMatches(
            stderr, r"No changes to .*/__init__\.py".replace("/", sep))
    self.assertNotRegex(
            stderr, r"No changes to .*/trivial\.py".replace("/", sep))