def test_nagios_alerts():
        """Test Nagios alert formatting with mock data"""
        config = ProviderConfig(
            id="test-nagios",
            name="Test Nagios",
            type="nagios",
            authentication={
                "url": "http://test.nagios.local/",
                "username": "test_user",
                "password": "test_pass"
            }
        )
    
>       provider = NagiosProvider(None, "test-nagios", config)
E       TypeError: Can't instantiate abstract class NagiosProvider with abstract methods dispose, validate_config

>           assert formatted_alert.severity == expected["severity"]
E           AssertionError: assert 'low' == <AlertSeverity.LOW: 'low'>
E            +  where 'low' = AlertDto(id='b7dc4d0b8b4795e3fedfebce796815ba', name='HTTP', status='resolved', severity='low', lastReceived='2024-01-...service_state='OK', host='web-server-01', output='HTTP OK: HTTP/1.1 200 OK - 1234 bytes in 0.123 second response time').severity