public Subject newSubject(final String identifier) {
        return newSubject(identifier, CONFIRMATION_METHOD);
    }
New subject element that uses the confirmation method
{@link #CONFIRMATION_METHOD}.

@param identifier the identifier
@return the subject
support/cas-server-support-saml-core-api/src/main/java/org/apereo/cas/support/saml/util/Saml10ObjectBuilder.java