addNode method

*[<Null safety>](https://dart.dev/null-safety)*

int addNode (String name, Vnode node)

Implementation

int addNode(String name, Vnode node) {
  if (!_isLegalObjectName(name)) {
    return ZX.ERR_INVALID_ARGS;
  }
  if (_entries.containsKey(name)) {
    return ZX.ERR_ALREADY_EXISTS;
  }
  final id = _nextId++;
  final e = _Entry(node, name, id);
  _entries[name] = e;
  _treeEntries.add(e);
  return ZX.OK;
}