default Set<String> resolveSupportedPromptValues(final WebContext context) {
        return resolveSupportedPromptValues(context.getFullRequestURL());
    }
Resolve prompt values.

@param context the context
@return the set
support/cas-server-support-oauth-api/src/main/java/org/apereo/cas/support/oauth/web/OAuth20RequestParameterResolver.java