title: What does Keras.io.preprocessing.sequence.pad_sequences do?
body: <p>The Keras documentation could be improved here. After reading through this, I still do not understand what this does exactly: <a href="https://keras.io/preprocessing/sequence/" rel="noreferrer">Keras.io.preprocessing.sequence.pad_sequences</a></p>
  
  <p>Could someone illuminate what this function does, and ideally provide an example?</p>