package tracing contains some helpers to make working with opentracing a tad simpler
Error logs error
Errorf logs error
Failure marks the current request as a failure
func NewSpan(ctx context.Context, tracer opentracing.Tracer, name string) (context.Context, opentracing.Span)
NewSpan pulls the span out of the context, creates a new child span, and updates the context callers must call span.Finish() when done important: the context must contain a span, otherwise you'll see a nilpointer panic here.