title: Is it possible to save and restore ANTLR4 state to avoid warm-up time?
body: <p>Using ANTLR v4, the parsing of the first file takes few seconds and the parsing of the following ones is almost instantaneous.</p>
  
  <p>Is it possible to save the state of ANTLR to avoid the warm-up time?</p>
  
  <p>Is <code>decisionToDFA</code> the only data structure that should be serialized?</p>