EndSpan ends a previously started span stored in the context. Has no effect if a Tracer has not been registered.
IsEnabled returns true if a Tracer has been registered.
NewTransport creates a new instrumenting http.RoundTripper for the registered Tracer. If no Tracer has been registered it returns nil.
Register will register the provided Tracer. Pass nil to unregister a Tracer.
StartSpan starts a trace span with the specified name, associating it with the provided context. Has no effect if a Tracer has not been registered.
Tracer represents an HTTP tracing facility.