[SOLVED]Adding subitems to ListModel

[cmer4]

Hello folks, searched this forum and googled a bit but found no reply yet to the following important question:

ListModel can have elements added via simple ListModel.append command.

Is there a way to add data to the element highlighted below? (e.g. to add a subitem to the ListModel via append command?)

@ListElement {
itemTitle: "Item title 1"
attributes: [
ListElement { subItemTitle: "Subitem title 1/1" } // Is there a way to add these using append?
ListElement { subItemTitle: "Subitem title 2/1" }
]
}@

UPDATE: well ofc course this was pretty lame...:

Solution:
@testModel.append({"itemTitle":"Item title 2", "attributes":[{"subItemTitle":"Subitem title 1/2"}]})@

But truth is - for people like me this is supposed to be in the documentation...