in src/plugins/HttpPlugin.ts [93:108]
const responseCB = function (this: any, res: any) {
// may wrap callback instead of event because it procs first
span.resync();
copyStatusAndWrapEmit(res);
try {
if (callback) return callback.apply(this, arguments);
} catch (err) {
span.error(err);
throw err;
} finally {
span.async();
}
};