docs: public Map<String, Map<String, INDArray>> rnnGetPreviousStates() {
          Map<String, Map<String, INDArray>> states = new HashMap<>();
          for (Layer l : layers) {
              if(l instanceof org.deeplearning4j.nn.layers.wrapper.BaseWrapperLayer){
                  l = ((org.deeplearning4j.nn.layers.wrapper.BaseWrapperLayer)l).getUnderlying();
              }
              if (l instanceof RecurrentLayer) {
                  states.put(l.conf().getLayer().getLayerName(), ((RecurrentLayer) l).rnnGetPreviousState());
              }
          }
          return states;
      }