ServiceInsight.Models.StoredMessage.GetHeaderByKey C# (CSharp) Method

        public string GetHeaderByKey(string key, string defaultValue = "")
        {
            //NOTE: Some keys start with NServiceBus, some don't
            var keyWithPrefix = "NServiceBus." + key;
            var pair = Headers.FirstOrDefault(x => x.Key.Equals(key, StringComparison.InvariantCultureIgnoreCase) ||
                                                   x.Key.Equals(keyWithPrefix, StringComparison.InvariantCultureIgnoreCase));
            return pair == null ? defaultValue : pair.Value;
        }

 public ExceptionDetails(StoredMessage message)
 {
     ExceptionType = message.GetHeaderByKey(MessageHeaderKeys.ExceptionType);
     Message       = message.GetHeaderByKey(MessageHeaderKeys.ExceptionMessage);
     Source        = message.GetHeaderByKey(MessageHeaderKeys.ExceptionSource);
     StackTrace    = message.GetHeaderByKey(MessageHeaderKeys.ExceptionStackTrace);
 }