new_contents: pytest_plugins = "logwatch"
  
  
  def test_logwatch_source(testdir):
      testdir.makeconftest("""
          import mock
          import pytest
  
          pytest_plugins = 'logwatch'
  
          mocksource = mock.Mock()
          mocksource.capture = mock.Mock(
              return_value=[('test_logwatch.txt', 'Error: This is a test error.')]
          )
  
          @pytest.hookimpl
          def pytest_lab_log_watch(logmanager):
              logmanager.register(mocksource)
              mocksource.prepare.assert_called_once_with()
              mocksource.prepare.reset_mock()
  
          @pytest.hookimpl
          def pytest_lab_process_logs(config, item, logs):
              mocksource.prepare.assert_called_once_with()
              mocksource.capture.assert_called_once_with()
  
              assert item.name == 'test_example'
              assert len(logs) == 1
              assert mocksource.ctl in logs.keys()
  
              mocklogs = logs[mocksource.ctl]
              assert len(mocklogs) == 1
              assert mocklogs == {
                  'test_logwatch.txt': 'Error: This is a test error.'
              }
      """)
  
      testdir.makepyfile("""
          def test_example():
              pass
      """)
  
      result = testdir.runpytest()
      assert result.ret == 0
  
subject: Add a simple unittest for logging support