I am using

DeleteRelationships

successfully. I noticed the calls are idempotent as I would expect. Removing something that doesn't exist returns success and a zedtoken. However, I wanted to play with detecting that a given relationship was not present on delete. I modified my

DeleteRelationshipsRequest

to add an

optional_preconditions

array containing a single

Precondition

where

OPERATION_MUST_MATCH

was the value of

operation

and the

filter

value was the same as the `DeleteRelationshipsRequest`'s

relationship_filter

value. This did not change the response at all. Is there a way to detect the deletion of something that does not exist? If yes, what in my request is not correct? If no, what is the exact meaning of the

Preconditions

contained in

optional_preconditions

? TIA!