Function construct 

pub(super) fn construct(
    scope: Scope<'_, Timestamp>,
    config: &LoggingConfig,
    metrics_registry: MetricsRegistry,
    now: Instant,
    start_offset: Duration,
    worker_config: Rc<ConfigSet>,
    workers_per_process: usize,
) -> Return

Constructs the logging dataflow fragment for Prometheus metrics.