protected java.util.List<DataSource> getPerformanceData(String host, String service)
	{
		String entity = host;
		if (service != null)
			entity += " | " + service;
		// System.out.println("sparkline entity: " + entity);

		PerformanceDataPerElement element = performanceData.get(entity);
		if (element != null)
			return element.getAllDataSources();

		return null;
	}