private static boolean isSlash(byte b) {
        switch (b) {
            case '/':
            case '\\':
                return true;
            default:
                return false;
        }
    }
Marks this {@link RequestTarget} as stored in {@link RequestTargetCache} so that it doesn't
try to store again.
core/src/main/java/com/linecorp/armeria/internal/common/DefaultRequestTarget.java