Iterator<Feature> features = featureSource.getFeatures(chr, start, end);
int count = countNonNullFeatures(features);
assertTrue("No features read" , count > 0);
assertTrue("No longest feature", geneTrackingSource.getLongestFeature(chr) > 0);
DataTile dataTile = geneTrackingSource.getRawData(chr, start, end);
assertNotNull("No fpkm data returned", dataTile);
assertFalse(dataTile.isEmpty());
}