Question about TestHBaseStore.assertTopLevelUnionsNull()

[Apostolis Giannakidis <ap...@gmail.com>]

Hello all,

I have a question regarding the test
case TestHBaseStore.assertTopLevelUnionsNull().

This test case creates a WebPage persistent object, sets its URL to a
custom URL and sets the "content" to be null. Then it persists the object
into the datastore.

Next, it performs 2 checks.

1) It uses the datastore to get the persistent using the same key and
specifies only the "content" field. Then it checks to see if the returned
value from the datastore.get() is null. If it is null then it passes the
check.

2) It checks directly into the backend database to make sure that the
"content" field is empty (null).

My question is this:
I can understand the 2nd check. It seems very logical.
However, the *1st* check does not seem logical to me. Since it uses the
datastore.get(), a persistent object *will* be returned not matter if the
"content" field is null or not. The object has been persisted into the
backend database, therefore, the get() method *will* return a persistent
object, *regardless* of the value of the "content" field. So, why does it
check to see if the get() method returned null? Is my understanding wrong?

Thank you very much for your help.

Best regards,
Apos