public static void putPrincipal(final RequestContext requestContext, final Principal authenticationPrincipal) {
        requestContext.getFlowScope().put("principal", authenticationPrincipal);
    }
Put principal.

@param requestContext          the request context
@param authenticationPrincipal the authentication principal
core/cas-server-core-web-api/src/main/java/org/apereo/cas/web/support/WebUtils.java