code: function () {
  
              // This check looks a little strange, but it suits what we're trying
              // to do: as we're walking through the children, a child node that has moved
              // from one parent to another will be found but would look like some kind
              // of insert. The check that we're doing here is looking up the current
              // child's ID in the *old* map and seeing if this child used to have a
              // different parent.
              var possiblyMovedElement = oldNodeMap[newChild.tagID];
              if (possiblyMovedElement &&
                      newParent.tagID !== getParentID(possiblyMovedElement)) {
                  newEdit = {
                      type: "elementMove",
                      tagID: newChild.tagID,
                      parentID: newChild.parent.tagID
                  };
                  moves.push(newEdit.tagID);
                  newEdits.push(newEdit);
  
                  // this element in the new tree was a move to this spot, so we can move
                  // on to the next child in the new tree.
                  newIndex++;
                  return true;
              }
              return false;
          }
docs: Adds an elementMove edit if the parent has changed between the old and new trees.
  These are fairly infrequent and generally occur if you make a change across
  tag boundaries.
  
  @return {boolean} true if an elementMove was generated