{
  instance: new (class {})(),

  "with props": new (class {
    x = 1;
  })(),
}

--

instance:
/<anonymous>(...)
/<anonymous>(...)
{
  "/<anonymous>": "/..."
}

with props:
/<anonymous>(x:1)
/<anonymous>(
  x: 1
)
{
  "/<anonymous>": {
    x: 1
  }
}