public double getProb(String[] keys) {

			if (this.finished) {

				double logProb = 0.0;
				for (int i = 0; i < 16; i++) {
					double ratio;
					if (features.get(i).containsKey(keys[i])) {
						ratio = (double) features.get(i).get(keys[i]) / count;
					} else {
						ratio = 0.0001;
					}
					logProb += Math.log(ratio);
				}

				return logProb;
			} else {
				throw new RuntimeException("RandomFerns: please call finish() first and then get probs");
			}
		}