 itself a reference to another
 catalog -- that is, a catalog cannot both refer to another
 <em>and</em> contain elements or other attributes.</div>
<dl><dt><span class="strong">Parameters:</span></dt><dd><code>entity</code> - the information about the URI resource mapping to be
       added to the catalog.</dd>
<dt><span class="strong">Throws:</span></dt>
<dd><code><a href="../../../../../org/apache/tools/ant/BuildException.html" title="class in org.apache.tools.ant">BuildException</a></code> - if this is 