code: function getRootSvg() {
    var childNodes = document.body.childNodes;
    var length = childNodes.length;
    for (var k = 0; k < length; k++) {
      var node = childNodes[k];
      if (node.tagName === 'svg' || node.tagName === 'SVG') {
        return node;
      }
    }
    return false;
  }
docs: Document root <svg> with defs and icons