old_contents: 
  from click.testing import CliRunner
  
  from pcap_compare.cli import main
  
  
  def test_main():
      runner = CliRunner()
      result = runner.invoke(main, [])
  
      assert result.output == '()\n'
      assert result.exit_code == 0
  
new_contents: import pytest
  from click.testing import CliRunner
  
  from pcap_compare import PcapCompare
  from pcap_compare.cli import main
  
  
  def test_pcap_compare():
      pc = PcapCompare()
      pytest.skip()
  
  
  def test_main():
      runner = CliRunner()
      result = runner.invoke(main, [])
  
      assert result.output == '()\n'
      assert result.exit_code == 0
  
subject: Add test stub