NIFI-16181 Make MockProcessSession#commitAsync null safe

[awelless]

Summary

NIFI-16181

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  • JDK 21
  • JDK 25

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[exceptionfactory]

Thanks for raising this issue @awelless.

On initial review, it looks like the onSuccess and onFailure inputs should use Objects.requireNonNull() to align with current behavior expectations

[exceptionfactory]

On closer review, it looks like the other ProcessSession implementations allow null, so this approach aligns with that behavior

[exceptionfactory]

Thanks again for adjusting the MockProcessSession behavior to align with standard implementation @awelless, looks good.