de> - a Map of properties for use by the 
 persistence provider. These properties may be used to
 override the values of the corresponding elements in 
 the <code>persistence.xml</code> file or specify values for 
 properties not specified in the <code>persistence.xml</code>
 (and may be null if no properties are specified).</dd>
<dt><span class="returnLabel">Returns:</span></dt>
<dd>EntityManagerFactory for the persistence unit, 
 or null if the provider is not the right provider</dd>
</dl>
</li>
</ul>
<a 