public Formatter(IFormatterSettingsFactory settingsFactory, ILogger <Formatter> logger = null)
 {
     _settingsFactory = settingsFactory;
     _logger          = logger;
 }
 public Formatter(FormatterSettings settings, ILogger <Formatter> logger = null)
 {
     _logger          = logger;
     _settingsFactory = new DummyFormatterSettingsFactory(settings ?? new FormatterSettings());
 }