refactor(internals): make prop optional

src/container/EdgeRenderer/utils.ts

@@ -168,7 +168,7 @@ export function isEdgeVisible({
 
 export function getNodeData(nodeInternals: NodeInternals, nodeId: string): [Rect, NodeHandleBounds | null, boolean] {
   const node = nodeInternals.get(nodeId);
-  const handleBounds = node?.[internalsSymbol].handleBounds || null;
+  const handleBounds = node?.[internalsSymbol]?.handleBounds || null;
 
   const isInvalid =
     !node ||

src/container/NodeRenderer/index.tsx

@@ -118,8 +118,8 @@ const NodeRenderer = (props: NodeRendererProps) => {
             isConnectable={isConnectable}
             resizeObserver={resizeObserver}
             dragHandle={node.dragHandle}
-            zIndex={node[internalsSymbol].z ?? 0}
-            isParent={!!node[internalsSymbol].isParent}
+            zIndex={node[internalsSymbol]?.z ?? 0}
+            isParent={!!node[internalsSymbol]?.isParent}
             noDragClassName={props.noDragClassName}
             noPanClassName={props.noPanClassName}
           />