protected void appendLogEvent(final LogEvent logEvent, final StringMap contextData) {
        val appender = configuration.getAppender(appenderRef.getRef());
        appender.append(finalizeLogEvent(logEvent, contextData));
    }
Build google cloud appender.

@param name           the name
@param projectId      the project id
@param flattenMessage the flatten message
@param appenderRef    the appender ref
@param filter         the filter
@param config         the config
@return the google cloud appender
support/cas-server-support-gcp-logging/src/main/java/org/apereo/cas/logging/GoogleCloudAppender.java