Function cancel_and_forget_async_fetch 

pub fn cancel_and_forget_async_fetch(
    request_ids: Vec<RequestId>,
    core_resource_thread: &CoreResourceThread,
)

Instruct the resource thread to cancel an existing request. Does nothing if the request has already completed or has not been fetched yet. This also “forgets” the request, which means that no further callbacks will be called when canceled.