code: function (el, parentNode) {
                      // updates the text of the text node
                      update = function (newVal) {
                          node.nodeValue = "" + newVal;
                          teardownCheck(node.parentNode);
                      };
  
                      var parent = getParentNode(el, parentNode),
                          node = document.createTextNode(binding.value);
  
                      // When iterating through an Observe.List with no DOM
                      // elements containing the individual items, the parent
                      // is sometimes incorrect not the true parent of the
                      // source element. (#153)
                      if (el.parentNode !== parent) {
                          parent = el.parentNode;
                          parent.insertBefore(node, el);
                          parent.removeChild(el);
                      } else {
                          parent.insertBefore(node, el);
                          parent.removeChild(el);
                      }
                      setupTeardownOnDestroy(parent);
                  }
docs: If we are escaping, replace the parentNode with a text node who's value is `func`'s return value.