Unsetting URI segments in CI instance

I'm a contractor working on upgrading a client's application from CI1 to CI4 (4.4.4 to be precise). There is a function in the legacy code that gets a value from a URI segment and then unsets that segment so that it doesn't interfere with routing. I've looked at the HTTP URI class and segments is now a protected property (and will be private in the future) so accessing the segments property directly as this code does isn't going to continue to work. I can use getSegments for that portion of the code, but I don't know how to handle the unsetting of segments as they do in that last if statement. Is there a way to unset segments in the CI instance? Should this be handled some other way?

In the legacy code this function is in a helper which is only ever accessed from a pre-controller hook. In the new code, I'll be moving this function to a filter.

Code:

function getActiveCredential() {
        $CI =& get_instance();

        // Grab the last segment of the URL
        $lastSegment = count($CI->uri->segments);
        $activeCredential = $lastSegment > 0 ? $CI->uri->segments[$lastSegment] : null;
        $activeCredential = is_numeric($activeCredential) ? $activeCredential : null;

        // Now unset it, so it doesn't affect the controllers
        if ($lastSegment > 0 && is_numeric($activeCredential)) {
            unset($CI->uri->segments[$lastSegment]);
            unset($CI->uri->rsegments[$lastSegment]);
        }

        return $activeCredential;
    }