in bindings/xlb/src/edge_binding.ts [73:83]
addHeader(key: string, value: string) {
this.resp.setHeaders.push(
create(HeaderValueOptionSchema, {
header: {
key: key,
rawValue: new TextEncoder().encode(value),
},
appendAction: HeaderValueOption_HeaderAppendAction.ADD_IF_ABSENT,
}),
);
}