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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def run(self):
 """Runs validation of all submissions."""

    cmd = ['gsutil', 'ls', os.path.join(self.source_dir, '**')]
    try:
      files_list = subprocess.check_output(cmd).split('\n')
    except subprocess.CalledProcessError:
      logging.error('Can''t read source directory')
    all_submissions = [
        s for s in files_list
        if s.endswith('.zip') or s.endswith('.tar') or s.endswith('.tar.gz')
    ]
    for submission_path in all_submissions:
      self.validate_and_copy_one_submission(submission_path)
    self.stats.log_stats()
    self.save_id_to_path_mapping()
    if self.containers_file:
      with open(self.containers_file, 'w') as f:
        f.write('\n'.join(sorted(self.list_of_containers)))