We won't actually get the opportunity to check for 404s here, since those are considered errors (and will thus terminate the signal).

Instead, we'll need to catch errors and translate those into NO:

```objc
return [[[self
    enqueueRequest:request resultClass:nil]
    reduceEach:^(NSHTTPURLResponse *response, id _) {
        return @(response.statusCode == 204);
    }]
    catch:^(NSError *error) {
        NSNumber *statusCode = error.userInfo[OCTClientErrorHTTPStatusCodeKey];
        if (statusCode.integerValue == 404) {
            return [RACSignal return:@NO];
        } else {
            return [RACSignal error:error];
        }
    }];
```