private static String nullOrEmptyToSlash(@Nullable String absolutePathRef) {
        if (Strings.isNullOrEmpty(absolutePathRef)) {
            return "/";
        }

        checkArgument(absolutePathRef.charAt(0) == '/',
                      "absolutePathRef: %s (must start with '/')", absolutePathRef);
        return absolutePathRef;
    }
Extracts path, query and fragment portions of the {@link URI}.
resteasy/src/main/java/com/linecorp/armeria/client/resteasy/ArmeriaJaxrsClientEngine.java