>DebugSemanticsDumpOrder</code>.</p>
<p>The system retains the nodes that are currently reachable from the root.
A given update need not contain information for nodes that do not change
in the update. If a node is not reachable from the root after an update,
the node will be discarded from the tree.</p>
<p>The <code>flags</code> are a bit field of <a href="../../dart-ui/SemanticsFlag-class.html">SemanticsFlag</a>s that apply to this node.</p>
<p>The <code>actions</code> are a bit field of <a href="../../dar