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: log.rs
    path of file: ./repos/encore/runtimes/core/src/trace
    
    the code of the file until where you have to start completion: use std::convert::Infallible;
use std::pin::Pin;
use std::sync::Arc;
use std::task::{Context, Poll};

use crate::api::reqauth::platform;
use bytes::Bytes;

use crate::model;
use crate::trace::eventbuf::signed_to_unsigned_i64;
use crate::trace::protocol::{EventType, TRACE_VERSION};
use crate::trace::time_anchor::TimeAnchor;
use crate::trace::Tracer;

pub struct ReporterConfig {
    pub app_id: String,
    pub env_id: String,
    pub deploy_id: String,
    pub app_commit: String,
    pub trace_endpoint: reqwest::Url,
    pub platform_validator: Arc<platform::RequestValidator>,
}

/// Sends traces to the trace server.
#[must_use]
pub struct Reporter {
    rx: tokio::sync::mpsc::UnboundedReceiver<TraceEvent>,
    anchor: TimeAnchor,
    http_client: reqwest::Client,
    config:
    
    fn header(&self, anchor: &TimeAnchor) -> Bytes {
        let event_type = self.event.typ;
        let event_id = self.event.id.0;
        let trace_id = &self.event.span.0 .0;
        let span_id = &self.event.span.1 .0;
        let ln = self.event.data.len();

        // Compute the timestamp, relative to the anchor's timestamp.
        let ts = self
            .event
            .ts
            .saturating_duration_since(anchor.instant)
            .as_nanos() as i64;
        let ts = signed_to_unsigned_i64(ts);

        Bytes::from(vec![
            // Event type, 1 byte
            event_type as u8,
            // Event ID, 8 bytes
            event_id as u8,
            (event_id >> 8) as u8,
            (event_id >> 16) as u8,
            (event_id >> 24) as u8,
            (event_id >> 32) as u8,
            (event_id >> 40) as u8,
            (event_id >> 48) as u8,
            (event_id >> 56) as u8,
            // Timestamp, 8 bytes
            ts as u8,
            (ts >> 8) as u8,
            (ts >> 16) as u8,
            (ts >> 24) as u8,
            (ts >> 32) as u8,
            (ts >> 40) as u8,
            (ts >> 48) as u8,
            (ts >> 56) as u8,
            // Trace ID, 16 bytes
            trace_id[0],
            trace_id[1],
            trace_id[2],
            trace_id[3],
            trace_id[4],
            trace_id[5],
            trace_id[6],
            trace_id[7],
            trace_id[8],
            trace_id[9],
            trace_id[10],
            trace_id[11],
            trace_id[12],
            trace_id[13],
            trace_id[14],
            trace_id[15],
            // Span ID, 8 bytes
            span_id[0],
            span_id[1],
            span_id[2],
            span_id[3],
            span_id[4],
            span_id[5],
            span_id[6],
            span_id[7],
            // Event data length, 4 bytes
            ln as u8,
            (ln >> 8) as u8,
            (ln >> 16) as u8,
            (ln >> 24) as u8,
        ])
    }