title: Multiple values in java.util.Properties
body: <p>It seems that java.util.Properties assumes one value per propery key.  That is,</p>
  
  <pre><code>foo=1
  foo=2
  </code></pre>
  
  <p>is not expected,</p>
  
  <p>Is there a class for this kind of multi-value property sheet, which also provides the load method?</p>