in Sources/Tracing/Tracer.swift [33:49]
func startSpan(
_ operationName: String,
baggage: Baggage,
ofKind kind: SpanKind,
at time: DispatchWallTime
) -> Span
/// Export all ended spans to the configured backend that have not yet been exported.
///
/// This function should only be called in cases where it is absolutely necessary,
/// such as when using some FaaS providers that may suspend the process after an invocation, but before the backend exports the completed spans.
///
/// This function should not block indefinitely, implementations should offer a configurable timeout for flush operations.
func forceFlush()
}
extension Tracer {