code: function insertRight(parent, node) {
  	var index = parent.length - 1;
  	parent[index] = node;
  	parent.sizes[index] = (0, _util.length)(node) + (index > 0 ? parent.sizes[index - 1] : 0);
  }
docs: Helperfunctions for _concat. Replaces a child node at the side of the parent.