IPortDefaults

const node1 = graph.createNode()
const node2 = graph.createNode()
const port1_1 = graph.addPort(node1)
const port1_2 = graph.addPort(node1)
const port2 = graph.addPort(node2)
const edge1 = graph.createEdge(port1_1, port2)
const edge2 = graph.createEdge(port1_2, port2)

// enable auto cleanup
graph.nodeDefaults.ports.autoCleanUp = true
graph.remove(edge1)
// port1_1 is removed with the edge
console.log(graph.contains(port1_1)) // false
// port2 is not removed since edge2 still is linked to it
console.log(graph.contains(port2))
// disable auto cleanup
graph.nodeDefaults.ports.autoCleanUp = false
graph.remove(edge2)
// no port is removed with the edge now
console.log(graph.contains(port1_2)) // true
console.log(graph.contains(port2)) // true

const n1 = graph.createNodeAt(new Point(0, 0))
const n2 = graph.createNodeAt(new Point(0, 50))
const n3 = graph.createNodeAt(new Point(0, 100))
const n4 = graph.createNodeAt(new Point(0, 150))

const defaultStyle = new NodeStylePortStyleAdapter({
  nodeStyle: new ShapeNodeStyle(),
  renderSize: new Size(5, 5)
})
graph.nodeDefaults.ports.style = defaultStyle

// share style instances
graph.nodeDefaults.ports.shareStyleInstance = true
const p1 = graph.addPort(n1)
const p2 = graph.addPort(n2)
// p1.style === defaultStyle; p2.style === defaultStyle; p1.style === p2.style;
defaultStyle.renderSize = new Size(10, 10) // p1 and p2 both get larger

// clone style instances
graph.nodeDefaults.ports.shareStyleInstance = false
const p3 = graph.addPort(n3)
const p4 = graph.addPort(n4)
// p3.style !== defaultStyle; p4.style !== defaultStyle; p3.style !== p4.style;
defaultStyle.renderSize = new Size(20, 20) // p3 and p4 don't change their size