tID</code> method for all <code>MessageInfo</code> objects
 passed to the <code>secureRequest</code> method of the returned ClientAuthContext.</dd>
<dd><code>clientSubject</code> - A Subject that represents the source of the service request to be secured by the acquired
 authentication context. The principals and credentials of the Subject may be used to select or acquire the
 authentication context. If the Subject is not null, additional Principals or credentials (pertaining to the source of
 the request) 