Trigger: State node testing

According to the Node-Red Help you can test a “Trigger: State” node by injecting a object in the input, inject msg.payload with following object.
{
“entity_id”: “test_entity”,
“old_state”: {
“state”: “on”
},
“new_state”: {
“state”: “off”
}
}

I can’t get that to work. Any idea what I’m doing wrong?