Function decorate_actual 

pub fn decorate_actual(
    cors: &Cors,
    origins: &CompiledCorsOrigins,
    origin: Option<&HeaderValue>,
    resp_headers: &mut HeaderMap,
)

Decorate an ACTUAL (non-preflight) response with the route’s CORS headers (DW-027). No-ops when the request carried no Origin or an origin the policy does not allow. origins is the policy’s snapshot-compiled origin set (see preflight_response).