Retrieving EA 'descendants_action' from a network object using WAPI

[#1]

In the WAPI docs extensible attributes section there is the following example:

"attr": {
     "value": <the extattr value>,
     # The following is a read-only field
     "inheritance_source": <reference to the object this EA is inheriting from>,

     # The following are write-only fields
     "inheritance_operation": one of 'INHERIT', 'DELETE' or 'OVERRIDE'
     "descendants_action": {
           "option_delete_ea": one of 'REMOVE' or 'RETAIN'
           "option_with_ea": one of 'CONVERT', 'INHERIT' or 'RETAIN'
           "option_without_ea": one of 'INHERIT' or 'NOT_INHERIT'
     }
}

I've successfully used this syntax to define a value for descendants_action for extensible attributes attached to a network object.  What i'm struggling to find is a WAPI endpoint to retrieve this same property.  When i return extattrs the descendants_action property is not present.

Does anyone have an example WAPI call to retrieve the configured value for descendants_action for a given extensible attribute that has inheritance enabled.  Bonus points if you can use a network object in the example :-)

Thanks!

[#2]

I'm realizing now these might be just one-time operations and therefore not available via the API for read.  That didn't dawn on me when i was first looking into this :-)