code: public Vec feedfoward(Vec x)
      {
          Vec a_lprev = x;
          for (int l = 0; l < layersActivation.size(); l++)
          {
              Vec z_l = new DenseVector(layerSizes[l+1]);
              z_l.zeroOut();
              W.get(l).multiply(a_lprev, 1.0, z_l);
  
              //add the bias term back in
              final Vec B_l = B.get(l);
              z_l.mutableAdd(B_l);
  
              layersActivation.get(l).activate(z_l, z_l);
              a_lprev = z_l;
          }
          
          return a_lprev;
      }
docs: Feeds the given singular pattern through the network and computes its
  activations
  @param x the input vector to feed forward through the network
  @return the final activation for this network