This example shows a collapsible tree with rectangular nodes arranged hierarchically, where clicking a node expands or collapses its descendants. The visualization uses D3.js v3 to lay out and render the tree as SVG, with nodes colored by their "type" field and links labeled with connection direction (SYNC or ASYN). Zooming and dragging are enabled through `d3.behavior.zoom`, and animations occur via the `update` function when nodes toggle open or closed. Data comes from a local JSON file with nested child arrays, and jQuery is used to support tooltip interactions.