When is contentKeySession(_:shouldRetry:reason:) called?

This is a question about AVContentKeySessionDelegate.

I want contentKeySession(_:didProvide:) to be called only once.
I thought I could control this with contentKeySession(_:shouldRetry:reason:), but this method is not called.
How can contentKeySession(_:shouldRetry:reason:) be called?

I would be happy to share your knowledge with you.

When is contentKeySession(_:shouldRetry:reason:) called?
 
 
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