code: func AnnotateSpanWithSignatureInfo(span opentracing.Span, signature *tasks.Signature) {
  	// tag the span with some info about the signature
  	span.SetTag("signature.name", signature.Name)
  	span.SetTag("signature.uuid", signature.UUID)
  
  	if signature.GroupUUID != "" {
  		span.SetTag("signature.group.uuid", signature.UUID)
  	}
  
  	if signature.ChordCallback != nil {
  		span.SetTag("signature.chord.callback.uuid", signature.ChordCallback.UUID)
  		span.SetTag("signature.chord.callback.name", signature.ChordCallback.Name)
  	}
  }
docs: // AnnotateSpanWithSignatureInfo ...