_createRankMedalSprite(rank) {
    const rankMedalResource = RSX[`season_rank_${SDK.RankFactory.rankedDivisionAssetNameForRank(rank)}`];
    const rankMedalSprite = new BaseSprite(rankMedalResource.img);
    // Sizing the medal sprite
    let medalSpriteWidth = 0;
    let medalSpriteHeight = 0;
    const divisionKey = SDK.RankFactory.rankedDivisionAssetNameForRank(rank);
    if (divisionKey == 'bronze') {
      medalSpriteWidth = 298.0;
      medalSpriteHeight = 180.0;
    } else if (divisionKey == 'silver') {
      medalSpriteWidth = 364.0;
      medalSpriteHeight = 180.0;
    } else if (divisionKey == 'gold') {
      medalSpriteWidth = 376.0;
      medalSpriteHeight = 180.0;
    } else if (divisionKey == 'diamond') {
      medalSpriteWidth = 284.0;
      medalSpriteHeight = 220.0;
    } else if (divisionKey == 'elite') {
      medalSpriteWidth = 316.0;
      medalSpriteHeight = 180.0;
    } else {
      // unknown division, default to bronze dimensions and warn
      medalSpriteWidth = 298.0;
      medalSpriteHeight = 180.0;
      console.warn(`LadderProgressLayer: Unknown division key - Rank ${model.get('rank_before')} gave division key ${divisionKey}`);
    }

    rankMedalSprite.scaleX = medalSpriteWidth / rankMedalSprite.getContentSize().width * 0.8;
    rankMedalSprite.scaleY = medalSpriteHeight / rankMedalSprite.getContentSize().height * 0.8;

    return rankMedalSprite;
  }
Iterates rank stars up by one and calls necessary animations
@param {String} rank
@private
@return {cc.Sprite} The new rank medal sprite, with no parent