SpanContext

SpanContext represents Span state that must propagate to descendant Spans and across process boundaries.

SpanContext is logically divided into two pieces: the user-level "Baggage" (see setBaggageItem and getBaggageItem) that propagates across Span boundaries and any Tracer-implementation-specific fields that are needed to identify or otherwise contextualize the associated Span instance (e.g., a

<trace_id, span_id, sampled> tuple).