code: function (valueWithUnit, elem, property) {
                  var unit = this.getUnit(valueWithUnit, property);
                  var value = parseFloat(valueWithUnit, 10);
                  return this.__convertToPixels[unit].call(this, value, elem, property);
              }
docs: Converts the value of a given CSS property of a given HTML element from any CSS units into pixels
  @param {String} valueWithUnit valid CSS value with unit e.g. "12pt", "1em", "10px"
  @param {HTMLElement} elem Needed if <code>valueWithUnit</code> is in "em" or "%", can be null
  otherwise.
  @param {String} property camelCased CSS property name
  @return {Number} value in pixels