default <U> U transform(Function<? super Seq<T>, ? extends U> transformer) {
        return transformer.apply(this);
    }
Transform this stream into a new type.
<p>
If certain operations are re-applied frequently to streams, this
transform operation is very useful for such operations to be applied in a
fluent style:
<p>
<pre><code>
Function&ltSeq&lt;Integer>, Seq&lt;String>> toString = s -> s.map(Objects::toString);
Seq&lt;String> strings =
Seq.of(1, 2, 3)
   .transform(toString);
</code></pre>
jOOL-java-8/src/main/java/org/jooq/lambda/Seq.java