All ids gives
{
  "id": 119,
  "name": "Test",
  "levels": [
    {
			"id": 606,
      "name": "level 5"
    },
    {
			"id": 605,
      "name": "level 4"
    },
    {
			"id": 604,
      "name": "level 3"
    },
    {
			"id": 603,
      "name": "level 2"
    }
  ],
  "forecast_level": {
		"id": 602,
    "name": "fk"
  }
}



Result:
Delete element: []
Update element: [{'id': 603, 'name': 'level 2'}, {'id': 604, 'name': 'level 3'}, {'id': 605, 'name': 'level 4'}, {'id': 606, 'name': 'level 5'}]
Create element: []

-------------------------------------------------------------------------------------------------------

Delete element:

{
	"id": 119,
  "name": "Test",
  "levels": [
    {
			"id": 605,
      "name": "level 4"
    },
    {
			"id": 604,
      "name": "level 3.1"
    },
    {
			"id": 603,
      "name": "level 2"
    }
  ],
  "forecast_level": {
    "name": "fk"
  }
}


Result:
Delete element: [{'id': 604, 'name': 'level 3'}, {'id': 606, 'name': 'level 5'}]Update element: [{'id': 603, 'name': 'level 2'}, {'id': 604, 'name': 'level 3.1'}, {'id': 605, 'name': 'level 4'}]
Create element: []

-------------------------------------------------------------------------------------------------------

{
	"id": 119,
  "name": "Test",
  "levels": [
		{
			"name": "level 6"
		},
		{
			"name": "level 5"
		},
    {
			"id": 605,
      "name": "level 4"
    },
    {
			"id": 604,
      "name": "level 3.1"
    },
    {
			"id": 603,
      "name": "level 2"
    }
  ],
  "forecast_level": {
    "name": "fk"
  }
}


Result:
Delete element: [{'id': 604, 'name': 'level 3'}, {'id': 606, 'name': 'level 5'}]
Update element: [{'id': 603, 'name': 'level 2'}, {'id': 604, 'name': 'level 3.1'}, {'id': 605, 'name': 'level 4'}]
Create element: [{'name': 'level 5'}, {'name': 'level 6'}]