Checkbox set true by default

Hi! How do I set a checkbox to be true/selected by default? Ideally without setting it’s ID to true in the node data array? Thank you!

You can see a bunch of examples of checkboxes in this sample: CheckBoxes

Note how the model has data with properties that can be specified in the definition of the checkbox (e.g. “choice1”, “choice2”) and that default to the data property name of “checked”, as used in the itemArrays.

Is there anything like

$("CheckBox", "MyCheckBox", { checked: true })

I am trying to adding to the node data array.

          $("CheckBox", "someBooleanDataPropertyName",
            { "ButtonIcon.visible": true },
            $(go.TextBlock, "This is a checkbox")),

thank you!