double[] hidden3 = new double[config.hiddenSize];
// Run dropout: randomly drop some hidden-layer units. `ls`
// contains the indices of those units which are still active
int[] ls = IntStream.range(0, config.hiddenSize)
.filter(n -> random.nextDouble() > params.getDropOutProb())
.toArray();
int offset = 0;
for (int j = 0; j < config.numTokens; ++j) {
int tok = feature.get(j);