Signals demand to upstream in a way that never allows for buffer overflow and thus never drops any element.
Signals unlimited demand to upstream and drops all elements from the buffer if the buffer is full and a new element arrives.
Signals unlimited demand to upstream and drops the oldest element from the buffer if the buffer is full and a new element arrives.
Signals unlimited demand to upstream and drops the incoming element if the buffer is full and a new element arrives.
Signals unlimited demand to upstream and drops the youngest element from the buffer if the buffer is full and a new element arrives.
Signals unlimited demand to upstream and completes the stream with an OverflowFailure
if the buffer is full and a new element arrives.