code: function(newnode, oldnode) {
  		var res = true,
  			prev = null;
  		var oldorder = this._assistant.order(oldnode.childNodes);
  		return Array.every(newnode.childNodes, function(node, index) {
  			if (node.nodeType === Node.ELEMENT_NODE) {
  				var id = this._assistant.id(node);
  				if (oldorder.has(id) && oldorder.has(prev)) {
  					res = oldorder.get(id) > oldorder.get(prev);
  				}
  				prev = id;
  			}
  			return res;
  		}, this);
  	}
docs: "soft" siblings can only be inserted and removed. This method verifies that
  elements retain their relative positioning before and after an update. Changing
  the ordinal position of elements is not supported since this might destruct UI
  state (moving eg. an iframe around using DOM methods would reload the iframe).
  TODO: Default support ordering and make it opt-out instead?
  @param {Element} newnode
  @param {Element} oldnode
  @returns {boolean}