);</pre>
<p>
Sets the chosen implementation for the given function class to
the implementation with the given name.  If no implementation
having the given name is found, the chosen implementation is
not changed.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>klass</code></em> :</span></p></td>
<td> a function class
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>name</code><