let mut headers = http::HeaderMap::new();
headers.insert(
  "traceparent",
  "00-0af7651916cd43dd8448eb211c80319c-00f067aa0ba902b7-01".parse().unwrap()
);

let context = trace_context::TraceContext::extract(&headers).unwrap();

let trace_id = u128::from_str_radix("0af7651916cd43dd8448eb211c80319c", 16);
let parent_id = u64::from_str_radix("00f067aa0ba902b7", 16);

assert_eq!(context.trace_id(), trace_id.unwrap());
assert_eq!(context.parent_id(), trace_id.ok());
assert_eq!(context.sampled(), true);