def test_plain_format_output(self):
        """Test the exact plain text format output"""
        # Set up environment for plain format
        with patch.dict('os.environ', {
            'MARQO_LOG_LEVEL': 'info',
            'MARQO_LOG_FORMAT': 'plain'
        }):
            importlib.reload(marqo_logging)
            # replace the stream object of the handler
            stream = io.StringIO()
            logging.root.handlers[0].stream = stream

            logger = logging.getLogger('test')
            logger.info("Test message")

            # Verify output format
            output = stream.getvalue()
            self.assertRegex(output,
                r'^\[\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2},\d{3}\] \d+ INFO test: Test message\n$')
Test the exact plain text format output
tests/unit_tests/marqo/test_logging.py