@Override
    public MapStream<K, V> unordered() {
        inner = inner.unordered();
        return this;
    }
Returns an equivalent stream that is
<a href="package-summary.html#Ordering">unordered</a>.  May return
itself, either because the stream was already unordered, or because
the underlying stream state was modified to be unordered.
<p>
This is an intermediate operation.

@return an unordered stream
common-parent/mapstream/src/main/java/com/speedment/common/mapstream/MapStream.java