protected function exportDotRenderExtras($debug_opts)
	{
		if (!empty($this->state_diagram_extras)) {
			echo "\tsubgraph cluster_extras {\n",
				"\t\tgraph [ margin = 10; ];\n",
				"\t\tcolor=transparent;\n\n";
			foreach($this->state_diagram_extras as $i => $e) {
				echo "\n\t# Extras ", str_replace("\n", " ", $i), "\n";
				echo $e, "\n";
			}
			echo "\t}\n";
		}
	}