takePendingPhantomAnchors method
Returns and clears the staged phantom-anchor relationships. Called by the render object during baseline consumption. Returns null when no relationships were staged (the common case — only animated reparents of hidden subtrees produce entries).
Internal contract — sliver-render-object-specific.
Implementation
Map<TKey, TKey>? takePendingPhantomAnchors() {
final result = _pendingPhantomAnchors;
_pendingPhantomAnchors = null;
return result;
}