old_contents: import subprocess
  
  class TestResult:
      def __init__(self, result):
          self.raw_result = result
          self.stdout = result.stdout.decode()
          self.stderr = result.stderr.decode()
  
  def run(args, should_fail=False):
      result = subprocess.run(args, capture_output=True)
      if should_fail:
          assert result.returncode > 0
      else:
          assert result.returncode == 0
      return TestResult(result)
  
  def fails(args):
      return run(args, should_fail=True)
  
  def prints_help(args):
      stderr = run(args, should_fail=True).stderr.decode()
      print(stderr)
      return stderr.startswith("Usage: ")
  
new_contents: import subprocess
  
  class TestResult:
      def __init__(self, result):
          self.raw_result = result
          self.stdout = result.stdout.decode()
          self.stderr = result.stderr.decode()
  
  def run(args, should_fail=False):
      result = subprocess.run(args, capture_output=True)
      if should_fail:
          assert result.returncode > 0
      else:
          assert result.returncode == 0
      return TestResult(result)
  
  def fails(args):
      return run(args, should_fail=True)
  
subject: Remove unnecessary prints_help() helper.