 the last value returned from the
closure is returned to the caller.</li></ol>

<p>If the sequence has no elements, <code>nextPartialResult</code> is never executed
and <code>initialResult</code> is the result of the call to <code>reduce(_:_:)</code>.</p>

<p><strong>Parameters:</strong>
  <strong>initialResult:</strong> The value to use as the initial accumulating value.
    <code>initialResult</code> is passed to <code>nextPartialResult</code> the first time the
    closure is executed.
  <strong>nextPart