WithDefaultTransaction configures the roundtripper to start a new APM transaction if no transaction is currently running using the factory function f.

WrapRoundTripper returns a http.Roundtripper wrapping r, reporting each request as a span to Elastic APM, if the request's context contains a sampled transaction Allows an optional default transaction to be configured for requests where context cannot be controlled for example client-go's cache management.

ClientOption sets options for tracing client requests.