in ingester/lib/src/symbolicator/mod.rs [815:824]
fn int_header<K: reqwest::header::AsHeaderName>(
response: &reqwest::Response,
name: K,
) -> Option<u64> {
response
.headers()
.get(name)
.and_then(|v| v.to_str().ok())
.and_then(|v| v.parse().ok())
}