You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: metrics.rs
    path of file: ./repos/holochain/crates/holochain_cascade/src
    
    the code of the file until where you have to start completion: use once_cell::sync::OnceCell;
use opentelemetry_api::{global::meter_with_version, metrics::*};

pub type CascadeDurationMetric = Histogram<f64>;

static DURATION_METRIC: OnceCell<CascadeDurationMetric> = OnceCell::new();

pub fn create_cascade_duration_metric() -> &'static CascadeDurationMetric {
    DURATION_METRI
    
pub fn create_cascade_duration_metric() -> &'static CascadeDurationMetric {
    DURATION_METRIC.get_or_init(|| {
        meter_with_version(
            "hc.cascade",
            None::<&'static str>,
            None::<&'static str>,
            Some(vec![]),
        )
        .f64_histogram("hc.cascade.duration")
        .with_unit(Unit::new("s"))
        .with_description("The time taken to execute a cascade query")
        .init()
    })
}