Sort Map by csv String value
<p>The below map contains String keys and Sting values. The values are a comma seperated String.
How can the Map be sorted by the fourth element of this String ?</p>

<p>So this Map : </p>

<pre><code>key1    a,b,c,1
key2    a,b,c,4
key3    a,b,c,3
key4    a,b,c,2
</code></pre>

<p>Becomes : </p>

<pre><code>key2    a,b,c,4
key3    a,b,c,3
key4    a,b,c,2
key1    a,b,c,1
</code></pre>

<p>Is this possible using a Map ?</p>
