NewTracer returns a tracer that will create spans via opentracing-go.

WithoutTracingOrphans is an option for NewTracer() to disable tracing spans if no parent span exist in the context.

WithTracer is an option for NewTracer() to use a custom function to retrieve the opentracing Tracer to use.

WithTracingTags is an option for NewTracer() to set the tags that are applied to all traces created by StartSpan().

DefaultTracingTags are the tags that are added by default to all traces.

Opt is a type for options that can be passed to NewTracer.