code: @Override
      public InputPreProcessor getInputPreprocessor(InputType... inputType) throws InvalidKerasConfigurationException {
          if (inputType.length > 1)
              throw new InvalidKerasConfigurationException(
                      "Keras SimpleRnn layer accepts only one input (received " + inputType.length + ")");
  
          return InputTypeUtil.getPreprocessorForInputTypeRnnLayers(inputType[0], layerName);
      }
docs: Gets appropriate DL4J InputPreProcessor for given InputTypes.
  
  @param inputType Array of InputTypes
  @return DL4J InputPreProcessor
  @throws InvalidKerasConfigurationException Invalid Keras configuration exception
  @see org.deeplearning4j.nn.conf.InputPreProcessor