rce</code>, <code>ConnectionPoolDataSource</code>, or
 <code>XADataSource</code>, must be indicated by the <code>className</code>
 element. The availability of the driver class will be assumed at runtime.
<p>
 DataSource properties should not be specified more than once. If
 the url annotation element contains a DataSource property that was also
 specified using the corresponding annotation element or was specified in
 the properties annotation element, the precedence order is undefined
 and implementation 