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: internal_metrics.rs
    path of file: ./repos/vector/src/sources
    
    the code of the file until where you have to start completion: use std::time::Duration;

use futures::StreamExt;
use serde_with::serde_as;
use tokio::time;
use tokio_stream::wrappers::IntervalStream;
use vector_lib::configurable::configurable_component;
use vector_lib::internal_event::{CountByteSize, InternalEventHandle as _};
use vector_lib::lookup::lookup_v2::Op
    
    async fn sets_tags() {
        let event = event_from_config(InternalMetricsConfig {
            tags: TagsConfig {
                host_key: OptionalValuePath::new("my_host_key"),
                pid_key: Some(String::from("my_pid_key")),
            },
            ..Default::default()
        })
        .await;

        let metric = event.as_metric();

        assert!(metric.tag_value("my_host_key").is_some());
        assert!(metric.tag_value("my_pid_key").is_some());
    }