where does ${spark.yarn.app.container.log.dir} resolve to on BigInsights on cloud?

Question

I'm trying to configure spark streaming logging. The spark docs state to set the following property:

log4j.appender.file_appender=${spark.yarn.app.container.log.dir}/spark.log

Where does spark.yarn.app.container.log.dir point to on a BigInsights on Cloud 4.2 Basic cluster?