I personally don't like static factories that much. They have their place, but half the JDK is now `.of` or `.from` or `.newInstance` or `.get`.

I'd really like to be able to define a constructor on sealed interfaces:

    sealed interface Path permits WindowsPath, UnixPath {
        public Path(String p) {
            if (isWindows()) {
                return new WindowsPath(p);
            }

            return new UnixPath(p);
        }
    }

That way user code to construct an object is always the same:

    var p = new Path(s);

Instead of:

    var p = Paths.get(s);