presto-main/src/main/java/io/prestosql/sql/planner/OptimizerStatsRecorder.java/OptimizerStatsRecorder/unexport
class OptimizerStatsRecorder:    synchronized void unexport(MBeanExporter exporter)
    {
        for (MBeanExport mbeanExport : mbeanExports) {
            mbeanExport.unexport();
        }
        mbeanExports.clear();
    }