resource demand estimation step is skipped if no services can be found

tools.descartes.pmx/src/tools/descartes/pmx/core/filter/resourcedemands/ResourceDemandFilter.java

@@ -146,6 +146,10 @@ public class ResourceDemandFilter extends AbstractTraceAnalysisFilter {
 		boolean error = errorBeforeTermination;
 
 		if (!error) {
+			if(timeSeriesMap.keySet().isEmpty()){
+				log.error("No service execution logs could be found");
+				return;
+			}
 			Librede.init();
 
 			WorkloadDescription workload = ConfigurationFactory.eINSTANCE
@@ -189,7 +193,6 @@ public class ResourceDemandFilter extends AbstractTraceAnalysisFilter {
 
 			addCPURecords(repository, range, conf);
 
-
 			runLibReDe(repository, conf);
 			
 			int fold = 0;