flare method
Emits a fire-and-forget observability flare name with data to the
out-of-band sink (the exploration host event stream the live arm adapts).
Emit-only — NEVER an inbound pipeline handle (invariant 1). Must not throw to
the caller in a way that breaks the flush (the host swallows errors). D-8.
Implementation
@override
void flare(String name, Map<String, String> data) =>
flares.add((name: name, data: data));