mutter/clutter/tests/conform/scripts/test-script-animation.json

{
  "type" : "ClutterAnimation",
  "id" : "test",
  "mode" : "easeInCubic",
  "duration" : 500,
  "object" : {
    "type" : "ClutterRectangle",
    "id" : "rect",
    "opacity" : 128,
    "width" : 100,
    "height" : 16,
    "color" : "white"
  }
}