concat

function concat(value1:GObject.Value, value2:GObject.Value):void {
    // Gjs wrapper for gst_value_list_concat()
}

Concatenates copies of value1 and value2 into a list. Values that are not of type #GST_TYPE_LIST are treated as if they were lists of length 1. dest will be initialized to the type #GST_TYPE_LIST.