fix code format

cat-home/src/main/java/com/dianping/cat/report/chart/BaseGraphCreator.java

@@ -270,8 +270,9 @@ public abstract class BaseGraphCreator implements LogEnabled {
 			Map<String, double[]> newCurrentValues = new LinkedHashMap<String, double[]>();
 			int step = m_dataExtractor.getStep();
 			
-			if (step <= 0)
+			if (step <= 0){
 				return allCurrentValues;
+			}
 			int minute = Calendar.getInstance().get(Calendar.MINUTE);
 			int removeLength = 60 / step - (minute / step);
 

cat-home/src/main/java/com/dianping/cat/report/page/userMonitor/graph/DefaultUserMonitGraphCreator.java

@@ -55,7 +55,7 @@ public class DefaultUserMonitGraphCreator extends BaseGraphCreator implements Us
 
 	@Override
 	protected Map<String, double[]> buildGraphData(MetricReport metricReport, List<MetricItemConfig> metricConfigs) {
-		return null;
+		throw new RuntimeException("unsupport in user monitor graph!");
 	}
 
 	private Map<String, LineChart> buildInfoChartData(final Map<String, double[]> datas, Date startDate, Date endDate,