Checks if a CustomObject exists for a given Query Predicate. Returns a 200 OK status if any CustomObjects match the Query Predicate or a 404 Not Found otherwise.
If an object with the given container/key exists, the object will be replaced with the new value and the version is incremented.
If the request contains a version and an object with the given container/key, then the version must match the version of the existing object. Concurrent updates to the same Custom Object returns a ConcurrentModification error even if the version is not provided.
Fields within `value` that have `null` values **are not saved**.
Deprecated