'Declaration
<EventMetricValueAttribute("SpanId", SummaryFunction.Count, "", Caption="Span Id", Description="The W3C Span of the Request Id if present")> Public Property SpanId As String
[EventMetricValue("SpanId", SummaryFunction.Count, "", Caption="Span Id", Description="The W3C Span of the Request Id if present")] public string SpanId {get; set;}