public MutableSpanContext(MutableSpanContext parentContext)
 {
     this.baggageItems = parentContext?.baggageItems ?? ImmutableDictionary <string, string> .Empty;
 }
 public override void Inject <TCarrier>(MutableSpanContext spanContext, IFormat <TCarrier> format, TCarrier carrier)
 {
     throw new NotSupportedException("Wire format is not supported");
 }