Function measure_debug_span 

pub fn measure_debug_span<T>(
    state: &DebugStateRef,
    log_state: &LogStateRef,
    clock: &Arc<dyn Fn() -> f64 + Send + Sync>,
    name: &str,
    run: impl FnOnce() -> T,
    channel: Option<String>,
) -> T

Times a synchronous function as one span while a debug session is active (TS measureDebugSpan) and returns its result. With debug disabled the function still runs and only the timing is skipped. The span is closed, and its entry emitted, even when the function panics (the source’s throw), and the panic then resumes. clock is read once when the span opens and once when it closes.