Cloudwatch Dashboard Variables in Custom Widgets

Hi,

I'm trying to develop a custom widget for a cloudwatch dashboard that uses a dashboard variable: https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/cloudwatch_dashboard_variables.html

Can you get access to the current variable value in the lambda of a custom dashboard widget? I don't see it in the sample lambda event shown here: https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/add_custom_widget_dashboard_about.html

I've printed out the event of a custom widget lambda and don't see any dashboard variable values there. I've also tried to add it to the custom widget parameters via $VARNAME, VARNAME, etc with no success. Maybe it's just not supported yet since dashboard variables are relatively new?

Thanks