code: public void rnnSetPreviousState(String layerName, Map<String, INDArray> state) {
          Layer l = verticesMap.get(layerName).getLayer();
          if(l instanceof org.deeplearning4j.nn.layers.wrapper.BaseWrapperLayer){
              l = ((org.deeplearning4j.nn.layers.wrapper.BaseWrapperLayer)l).getUnderlying();
          }
          if (l == null || !(l instanceof RecurrentLayer)) {
              throw new UnsupportedOperationException(
                      "Layer \"" + layerName + "\" is not a recurrent layer. Cannot set state");
          }
          ((RecurrentLayer) l).rnnSetPreviousState(state);
      }
docs: Set the state of the RNN layer, for use in {@link #rnnTimeStep(INDArray...)}
  
  @param layerName The name of the layer.
  @param state     The state to set the specified layer to