ConfigToJSON marshals a tracingconfig.Config to a JSON string.

FromSpanContext populates DistributedTracingExtension from a SpanContext.

JSONToConfig converts a JSON marshaled version of the tracingconfig.Config back to the structure.

StartChildSpan adds a child span to the trace parent in the given context.

ToSpanContext creates a SpanContext from a DistributedTracingExtension instance.