showPressToContinueNode(duration, buttonText, font, fontSize, textColor) {
    if (duration == null) { duration = 0.0; }
    if (buttonText == null) { buttonText = this.continueButtonText; }
    if (font == null) { font = this.continueButtonFont; }
    if (fontSize == null) { fontSize = this.continueFontSize; }
    if (textColor == null) { textColor = this.continueButtonTextColor; }

    return this.whenRequiredResourcesReady().then((requestId) => {
      if (!this.getAreResourcesValid(requestId)) return; // load invalidated or resources changed

      this.removeContinueNodes(duration);

      this.continueButtonText = buttonText;
      this.continueFontSize = fontSize;
      this.continueButtonFont = font;
      this.continueButtonTextColor = textColor;

      const continueButtonSprite = new ccui.Scale9Sprite(RSX.button_secondary.img);
      const continueButtonGlowSprite = new ccui.Scale9Sprite(RSX.button_secondary_glow.img);
      const continueButtonSize = continueButtonSprite.getContentSize();
      const continueButtonLabel = new cc.LabelTTF(this.continueButtonText, this.continueButtonFont, this.continueFontSize, null, cc.TEXT_ALIGNMENT_CENTER);
      continueButtonLabel.setFontFillColor(this.continueButtonTextColor);

      this.continueNode = new cc.ControlButton(continueButtonLabel, continueButtonSprite);
      this.continueNode.setPreferredSize(continueButtonSize);
      this.continueNode.setAdjustBackgroundImage(false);
      this.continueNode.setZoomOnTouchDown(false);
      this.continueNode.setBackgroundSpriteForState(continueButtonSprite, cc.CONTROL_STATE_NORMAL);
      this.continueNode.setBackgroundSpriteForState(continueButtonGlowSprite, cc.CONTROL_STATE_HIGHLIGHTED);
      this.addChild(this.continueNode, this.continueZOrder);

      // add as interactive
      this.addInteractiveElement(this.continueNode);

      if (this.isRunning()) {
        // resize when this is already running (in scene)
        // otherwise, resize will occur automatically on first init
        this.resizeContinueNodes();
      }

      if (duration != null && duration > 0.0) {
        this.continueNode.setOpacity(0.0);
        this.continueNode.fadeTo(duration, 255.0);
      }
    });
  }
Shows press to continue button and returns a promise.
@param {Number} [duration=0.0] time in seconds
@param {String} [buttonText=this.continueButtonText]
@param {String} [font=this.continueButtonFont]
@param {Number} [fontSize=this.continueFontSize]
@param {cc.Color} [textColor=this.textColor]
@returns {Promise}