Called by the (RNG)[trait.RNG.html] when there are one or more random numbers available
randomness in an
Iterator of available random numbers. The amount of
randomness available may increase if
randomness is not consumed
quickly so clients should not rely on iterator termination to finish
consuming random numbers.
The client returns either
Continue::More if the iterator did not have
enough random values and the client would like to be called again when
more is available, or
If randoness_available is triggered after a call to cancel() then error MUST be CANCEL and randomness MAY contain random bits.