initEntitySprites(spriteOptions) {
    spriteOptions || (spriteOptions = {});
    const scale = spriteOptions.scale || CONFIG.SCALE;
    const shadowOffset = (spriteOptions.shadowOffset || UnitSprite.prototype.shadowOffset) * scale;

    // update center offset for shadow offset
    this.centerOffset.y += shadowOffset;

    this.whenResourcesReady(this.getCardResourceRequestId()).then((cardResourceRequestId) => {
      if (!this.getAreResourcesValid(cardResourceRequestId)) return; // card has changed

      const { sdkCard } = this;
      spriteOptions.spriteIdentifier = this.getAnimResource().breathing;

      // entity sprite
      this.entitySprite = UnitSprite.create(spriteOptions);
      if (scale != null) { this.entitySprite.setScale(scale); }

      // shadow sprite
      this.shadowSprite = BaseSprite.create(RSX.unit_shadow.img);
      this.shadowSprite.setOpacity(200);

      // set positions
      // set center offset based on sprite size
      const contentSize = this.entitySprite.getContentSize();
      const centerPositionForSprite = this.getCenterPosition();
      centerPositionForSprite.y += contentSize.height - shadowOffset * 2.0;
      this.entitySprite.setPosition(centerPositionForSprite);
      this.shadowSprite.setPosition(this.getGroundPosition());

      // add sprites to scene
      this.addChild(this.entitySprite);
      this.addChild(this.shadowSprite, -9999);
    });
  }
*************************************************************************
 UnitNode
 var UnitNode = EntityNode
 UnitNode.create()
**************************************************************************