public static void putCasLoginFormViewable(final RequestContext context, final boolean viewable) {
        context.getFlowScope().put("casLoginFormViewable", viewable);
    }
Put cas login form viewable.

@param context  the context
@param viewable the viewable
core/cas-server-core-web-api/src/main/java/org/apereo/cas/web/support/WebUtils.java