iv class="block">Signal to the container (programmatically trigger) that it should start or continue a web/HTTP based authentication dialog with
 the caller.

 <p>
 Programmatically triggering means that the container responds as if the caller had attempted to access a constrained resource
 and acts by invoking a configured authentication mechanism (such as the <a href="../../../javax/security/enterprise/authentication/mechanism/http/HttpAuthenticationMechanism.html" title="interface in javax.security.enter