code: function normalize(node) {
    if (!(isElement(node) || isDocument(node) || isDocumentFragment(node))) {
      return;
    }
    if (!node.childNodes) {
      return;
    }
    var textRangeStart = -1;
    for (var i = node.childNodes.length - 1, n = void 0; i >= 0; i--) {
      n = node.childNodes[i];
      if (isTextNode(n)) {
        if (textRangeStart === -1) {
          textRangeStart = i;
        }
        if (i === 0) {
          // collapse leading text nodes
          collapseTextRange(node, 0, textRangeStart);
        }
      } else {
        // recurse
        normalize(n);
        // collapse the range after this node
        if (textRangeStart > -1) {
          collapseTextRange(node, i + 1, textRangeStart);
          textRangeStart = -1;
        }
      }
    }
  }
docs: Normalize the text inside an element
  
  Equivalent to `element.normalize()` in the browser
  See https://developer.mozilla.org/en-US/docs/Web/API/Node/normalize