public static AEADResult DecryptAll(this IAEADBlockCipher cipher, ReadOnlySpan <byte> input, Span <byte> output)
 {
     return(cipher.DecryptFinal(cipher.Decrypt(input, output)));
 }
 public static AEADResult Decrypt(this IAEADBlockCipher cipher, AEADResult previousResult)
 {
     return(cipher.Decrypt(previousResult.RemainingInput, previousResult.RemainingOutput));
 }