code: function (text, ret) {
              text = text || this._text;
  
              var strings = ("" + text).split("\n");
              var stringHeight = measureTextHeight(this);
              var textMetrics  = ret || this.getBounds();
  
              textMetrics.height = textMetrics.width = 0;
  
              for (var i = 0; i < strings.length; i++) {
                  textMetrics.width = Math.max(measureTextWidth(this, strings[i]), textMetrics.width);
                  textMetrics.height += stringHeight;
              }
              return textMetrics;
          }
docs: measure the given text size in pixels
  @name measureText
  @memberOf me.BitmapText.prototype
  @function
  @param {String} [text]
  @param {me.Rect} [ret] a object in which to store the text metrics
  @returns {TextMetrics} a TextMetrics object with two properties: `width` and `height`, defining the output dimensions