code: function (element, property, defaultValue) {
              var value = this.getStyle(element, property);
              if (this.pxRegExp.test(value)) {
                  return Math.round(parseFloat(value));
              }
              return defaultValue;
          }
docs: Calls getStyle(domElt, property) and returns the value as a number if it is in pixels. Otherwise, returns the
  provided default value.
  @param {HTMLElement} element The DOM element on which to retrieve a CSS property
  @param {String} property The CSS property to retrieve
  @param {Number} defaultValue default value to return in case getStyle does not return a value in pixels
  @return {Number}