code: function computedStyle(elem, pseudo, prop) {
      var result;
  
      if ('getComputedStyle' in window) {
        result = getComputedStyle.call(window, elem, pseudo);
        var console = window.console;
  
        if (result !== null) {
          if (prop) {
            result = result.getPropertyValue(prop);
          }
        } else {
          if (console) {
            var method = console.error ? 'error' : 'log';
            console[method].call(console, 'getComputedStyle returning null, its possible modernizr test results are inaccurate');
          }
        }
      } else {
        result = !pseudo && elem.currentStyle && elem.currentStyle[prop];
      }
  
      return result;
    }
docs: wrapper around getComputedStyle, to fix issues with Firefox returning null when
  called inside of a hidden iframe
  
  @access private
  @function computedStyle
  @param {HTMLElement|SVGElement} - The element we want to find the computed styles of
  @param {string|null} [pseudoSelector]- An optional pseudo element selector (e.g. :before), of null if none
  @returns {CSSStyleDeclaration}