static <T, U> U foldLeft(Stream<? extends T> stream, U seed, BiFunction<? super U, ? super T, ? extends U> function) {
        return foldLeft(seq(stream), seed, function);
    }
Fold a stream to the left.
<p>
<pre><code>
// "abc"
Seq.of("a", "b", "c").foldLeft("", (u, t) -> u + t)
</code></pre>
jOOL/src/main/java/org/jooq/lambda/Seq.java