List < Node < T >> function ( ) { return children ; }
access the node 's child nodes concode_field_sep Node<T> parent concode_elem_sep T value concode_elem_sep List<Node<T>> children concode_field_sep Set<T> flatten concode_elem_sep T getValue concode_elem_sep boolean hasAncestor concode_elem_sep boolean hasChild concode_elem_sep boolean[] concat concode_elem_sep Node<T> addChild concode_elem_sep void write concode_elem_sep boolean hasNextSibling