lements
of the collection using the provided function.</p>
<p>The iterable must have at least one element.
If it has only one element, that element is returned.</p>
<p>Otherwise this method starts with the first element from the iterator,
and then combines it with the remaining elements in iteration order,
as if by:</p>
<pre class="language-dart"><code>E value = iterable.first;
iterable.skip(1).forEach((element) {
  value = combine(value, element);
});
return value;
</code></pre>
<p>Example of calculating t