I looked up the function in the documentation.
Are you asking how to to get the Occurence for the this function?
I had to automate such enclosure creation, and i have experienced the same exact problem.
The API respond with "Wrong argument type" and i cannot understand why.
I assume it is broken, or the exact parameter types to pass are not properly documented.
I have only first level occurrencies to deal with, and it appear that simply create an array of occurrences (not references) is no good for that API.
Do anyone have a working example of this api using 1-level occurrencies assembly ?