code: def test_remove_duplicates(self):
      file_list = FileList()
      file_list.files = ["a", "b", "a", "g", "c", "g"]
      # files must be sorted beforehand (sdist does it)
      file_list.sort()
      file_list.remove_duplicates()
      self.assertEqual(file_list.files, ["a", "b", "c", "g"])
  
imports: import os
  import re
  import unittest
  from distutils import debug
  from distutils.log import WARN
  from distutils.errors import DistutilsTemplateError
  from distutils.filelist import glob_to_re, translate_pattern, FileList
  from test.test_support import captured_stdout, run_unittest
  from distutils.tests import support
label_desc: Use image node_id 7 for calling the FileListTestCase obj's underlying member method code with example usage: obj.test_remove_duplicates() without return types