async function simulateGameHandler(wantNewGame) {
  if (wantNewGame) {
    SAMPLE_GAME_STATE = game.generateOnePlay();
  }
  const featuresAndLabel = gameToFeaturesAndLabel(SAMPLE_GAME_STATE);
  ui.displaySimulation(SAMPLE_GAME_STATE, featuresAndLabel);
  ui.displayNumSimulationsSoFar();
}
Collects one random play of the game.  Processes the sample to generate
features and labels representation of the play.  Calls a UI method to render
the sample and the processed sample.
@param {bool} wantNewGame : If true, a new game is generated.