public static Map<String,Map<String,Double>> flattenFeatureWithDropout(FeatureVector featureVector,double dropout){
  long seed=random.nextLong();
  return flattenFeatureStreamToMap(flattenFeatureWithDropoutAsStream(featureVector,dropout,seed));
}

public static Map < String , Map < String , Double > > flattenFeatureWithDropout ( FeatureVector featureVector , double dropout ) { long seed = random . nextLong ( ) ; return flattenFeatureStreamToMap ( flattenFeatureWithDropoutAsStream ( featureVector , dropout , seed ) ) ; }
flatten a feature vector from example to a nested map of feature family - > ( feature - > value ) with dropout
