merge

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

Merges copies of value1 and value2. Values that are not of type #GST_TYPE_LIST are treated as if they were lists of length 1.

The result will be put into dest and will either be a list that will not contain any duplicates, or a non-list type (if value1 and value2 were equal).