code: function getStyleComputedProperty(element, property) {
    if (element.nodeType !== 1) {
      return [];
    }
    // NOTE: 1 DOM access here
    var css = getComputedStyle(element, null);
    return property ? css[property] : css;
  }
docs: Get CSS computed property of the given element
  @method
  @memberof Popper.Utils
  @argument {Eement} element
  @argument {String} property