static <T> Seq<T> seq(Optional<? extends T> optional) {
        
        // [#245] For the special kind of ugly client code...
        if (optional == null)
            return Seq.empty();
        
        return optional.map(Seq::of).orElseGet(Seq::empty);
    }
Wrap an <code>Optional</code> into a <code>Seq</code>.
jOOL/src/main/java/org/jooq/lambda/Seq.java