@Override
public Iterator<Locus> getFeatures(String chr, int start, int end) throws IOException {
//System.out.println(String.format("%s:%d-%d", chr, start, end));
if(generator.nextFloat() <= probSuccess){
//System.out.println("success");
Locus feature = new Locus(chr, start, Math.min(start + 50, end));
return Arrays.asList(feature).iterator();
}else{
try {
Thread.sleep(100);
} catch (InterruptedException e) {