A relation-graph demo for replaying whole-graph expand and collapse sequences over a fixed centered hierarchy. It loads one inline 39-node dataset, auto-fits the graph, auto-runs expand playback on mount, exposes global `Expand All` and `Collapse All` controls in a draggable helper window, and inherits secondary canvas settings plus image export utilities from a shared helper.

Whole-Graph Expand/Collapse Playback in a Centered Hierarchy

What This Example Builds

This example builds a full-height centered hierarchy viewer that replays branch visibility for the entire graph instead of leaving expansion to isolated node clicks. The canvas shows a root-centered subsystem-style diagram with orange circular nodes, straight gray labeled connectors, and a floating white helper window layered above the graph.

Users can replay Expand All and Collapse All, drag the he