private List<Feature> tstOperationBED(String pathA, String pathB,
CombinedFeatureSource.Operation operation, int expectedNumFeatures) throws Exception {
IgvTools igvTools = new IgvTools();
igvTools.doIndex(pathA, null, 1, 16000);
igvTools.doIndex(pathB, null, 1, 16000);
FeatureSource sourceA = TribbleFeatureSource.getFeatureSource(new ResourceLocator(pathA), genome);
FeatureSource sourceB = TribbleFeatureSource.getFeatureSource(new ResourceLocator(pathB), genome);
CombinedFeatureSource combinedFeatureSource = new CombinedFeatureSource(new FeatureSource[]{sourceA, sourceB}, operation);
Iterator<Feature> features = combinedFeatureSource.getFeatures("chr1", 0, (int) 1e6);
List<Feature> featureList = new ArrayList(10);