title: In Keras, How can i get 4D output from LSTM
body: <p>I want to implement a model with LSTM and one pooling layer which wants 4D input. However LSTM's output is 3D. How can i implement ?</p>
  
  <p>I want model</p>
  
  <pre><code>LSTM ( units:32, input_shape(batch_size,1,200),return_sequences:true)
  LSTM ( units:32, input_shape(batch_size,1,200),return_sequences:true)  //3D output
  pooling() //input_Shape(sample,row,col,channels)
  dense()
  </code></pre>