undertow/src/main/java/org/wildfly/extension/undertow/security/jaspi/JASPICSecurityContext.java
private MessageInfo buildMessageInfo() {
        ServletRequestContext servletRequestContext = exchange.getAttachment(ServletRequestContext.ATTACHMENT_KEY);
        GenericMessageInfo messageInfo = new GenericMessageInfo();
        messageInfo.setRequestMessage(servletRequestContext.getServletRequest());
        messageInfo.setResponseMessage(servletRequestContext.getServletResponse());
        // when calling cleanSubject, isMandatory must be set to true.
        messageInfo.getMap().put("javax.security.auth.message.MessagePolicy.isMandatory", "true");
        return messageInfo;

    }
private MessageInfo buildMessageInfo() {
        ServletRequestContext servletRequestContext = exchange.getAttachment(ServletRequestContext.ATTACHMENT_KEY);
        GenericMessageInfo messageInfo = new GenericMessageInfo();
        messageInfo.setRequestMessage(servletRequestContext.getServletRequest());
        messageInfo.setResponseMessage(servletRequestContext.getServletResponse());
        // when calling cleanSubject, isMandatory must be set to true.
        messageInfo.getMap().put("javax.security.auth.message.MessagePolicy.isMandatory", "true");
        return messageInfo;

    }
<p>
Builds the {@code MessageInfo} instance for the {@code cleanSubject()} call.
</p>

@return the constructed {@code MessageInfo} object.