presto-resource-group-managers/src/main/java/io/prestosql/plugin/resourcegroups/db/DbResourceGroupConfigurationManager.java/DbResourceGroupConfigurationManager/disableDeletedGroups
class DbResourceGroupConfigurationManager:    private synchronized void disableDeletedGroups(Set<ResourceGroupIdTemplate> deletedSpecs)
    {
        for (ResourceGroupIdTemplate resourceGroupIdTemplate : deletedSpecs) {
            for (ResourceGroupId resourceGroupId : configuredGroups(resourceGroupIdTemplate)) {
                disableGroup(groups.get(resourceGroupId));
            }
        }
    }