code: public INDArray[] output(boolean train, @NonNull INDArray[] input, INDArray[] inputMasks){
          return output(train, input, inputMasks, null);
      }
docs: Return an array of network outputs (predictions), given the specified network inputs
  Network outputs are for output layers only.
  
  @param train      If true: forward pass for training mode. False: test mode
  @param input      Input arrays to the netwonk
  @param inputMasks Optional input mask arrays (may be null)
  @return           Network output activations