How would one go about getting the inventory item (Blackstar or Azurastar) and checking to see if it is filled with a grand soul?

I define them as such and select the correct ids in the properties list:

It looks like the right way to declare them.

Soulgem Property Blackstar AutoSoulgem Property Azurastar Auto

Then I would go and check if the player has them and then set the property:

EVENT OnEffectStart(Actor akTarget, Actor akCaster)    if akCaster.getItemCount(Blackstar) >= 1        ; the same condition can be repeated for azurastar        if akCaster.Item(Blackstar).getSoul() != 1600            akCaster.Item(Blackstar).setSoul(1600)        endif    endifendEVENT

Obviously, this does not compile because we cannot get the item in the inventory nor can we get the properties.

I tried using google to find how to access the properties in creation kit but nothing was found
If anyone knows how to do what I am trying to do, let me know.

More importantly though as it would be more helpful if I try to mod something else:

Where is the documentation on the functions and how to access the property's methods?

I tried using names in creation kit wiki /Category:Object_Classes (I cant even post links in a support forum lol) and with variations of getX and setX but nothing compiles because said methods do not exist.
I can add and remove the item, but I cannot modify it, which is very strange not to have set methods in what is supposedly OOP.
So I figured, I could remove or add the item, but how am I supposed to pass on constructor values? Guess them?