lookup method

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

Vnode? lookup (String name)

Looks up a node for given name.

Returns null if no node if found.

Implementation

Vnode? lookup(String name) {
  var v = _entries[name];
  if (v != null) {
    return v.node;
  }
  return null;
}