code: function isUnwrappable(node, options) {
          if (!isHtmlElement(node)) {
              return false;
          }
  
          if (!isInlineNode(node)) {
              return true;
          }
  
          if (!isEditable(node, options)) {
              return true;
          }
  
  /*
          if (node.nodeType == 3 && options.ignoreWhiteSpace && !/[^\r\n\t ]/.test(node.data)
                  && (isUnwrappable(node.previousSibling, options) || isUnwrappable(node.nextSibling, options))) {
              return true;
          }
  */
  
          return unwrappableTagNamesRegex.test(node.tagName);
      }
docs: "An unwrappable node is an HTML element which may not be used where only
  phrasing content is expected (not counting unknown or obsolete elements,
  which cannot be used at all); or any Element whose display property computes
  to something other than 'inline', 'inline-block', or 'inline-table'; or any
  node whose parent is not editable."