presto-main/src/main/java/io/prestosql/spiller/AesSpillCipher.java/AesSpillCipher/throwCipherClosedIfNull
class AesSpillCipher:    private static <T> T throwCipherClosedIfNull(T value)
    {
        if (value == null) {
            throw new PrestoException(GENERIC_INTERNAL_ERROR, "Spill cipher already closed");
        }
        return value;
    }