public static long deriveChainId(long v) {
        if (v == LOWER_REAL_V || v == (LOWER_REAL_V + 1)) {
            return 0L;
        }
        return (v - CHAIN_ID_INC) / 2;
    }
@Test
    void deriveChainIdWhenMainNet() {
        long v = 37;

        long chainId = TransactionUtils.deriveChainId(v);

        assertEquals(1, chainId);
    }