How to sort Guava's MultiMap only by keys?
<p>I have MultiMap from Guava library. I want to sort it only by keys. I have tried:</p>

<pre><code>Multimap&lt;String, MyObj&gt; sortedMultiMap =
    TreeMultimap.create(Ordering.from(new Comparator&lt;String&gt;() {
        @Override
        public int compare(String lhs, String rhs) {
            //my comparison here
        }
    }), Ordering.natural());//i want not to sort values at all,MyObj doesn't implement Comparable
sortedMultiMap.putAll(notSortedMultiMap);
</code></pre>

<p>But as you can see, <em>TreeMultiMap.create</em> method has 2 arguments - comparators for keys and values. How i can sort MultiMap only by keys?</p>