alue of this argument may be null.</dd>
<dd><code>appContext</code> - A String that identifies the application messaging context for which the registered
 AuthConfigProvider is to be returned. The value of this argument may be null.</dd>
<dd><code>listener</code> - The RegistrationListener whose <code>notify</code> method is to be invoked if the corresponding
 registration is unregistered or replaced. The value of this argument may be null.</dd>
<dt><span class="returnLabel">Returns:</span></dt>
<dd>The imp