Tracer provides an interface for creating Spans and propagating context in-process.
Users may choose to use manual or automatic Context propagation. Because of that this class offers APIs to facilitate both usages.
Bind a span as the target's context or propagate the current one.
Any object to which a context need to be set
Returns the current Span from the current context if available.
If there is no Span associated with the current context, null is returned.
Span The currently active Span
Executes the function given by fn within the context provided by Span
The span that provides the context
The function to be executed inside the provided context