def _test_getchaintxstats(self):
        self.log.info("Test getchaintxstats")

        # Test `getchaintxstats` invalid extra parameters
        assert_raises_rpc_error(-1, 'getchaintxstats', self.nodes[0].getchaintxstats, 0, '', 0)

        # Test `getchaintxstats` invalid `nblocks`
        assert_raises_rpc_error(-1, "JSON value is not an integer as expected", self.nodes[0].getchaintxstats, '')
        assert_raises_rpc_error(-8, "Invalid block count: should be between 0 and the block's height - 1", self.nodes[0].getchaintxstats, -1)
        assert_raises_rpc_error(-8, "Invalid block count: should be between 0 and the block's height - 1", self.nodes[0].getchaintxstats, self.nodes[0].getblockcount())

        # Test `getchaintxstats` invalid `blockhash`
        assert_raises_rpc_error(-1, "JSON value is not a string as expected", self.nodes[0].getchaintxstats, blockhash=0)
        assert_raises_rpc_error(-8, "blockhash must be of length 64 (not 1, for '0')", self.nodes[0].getchaintxstats, blockhash='0')
        assert_raises_rpc_error(-8, "blockhash must be hexadecimal string (not 'ZZZ0000000000000000000000000000000000000000000000000000000000000')", self.nodes[0].getchaintxstats, blockhash='ZZZ0000000000000000000000000000000000000000000000000000000000000')
        assert_raises_rpc_error(-5, "Block not found", self.nodes[0].getchaintxstats, blockhash='0000000000000000000000000000000000000000000000000000000000000000')
        blockhash = self.nodes[0].getblockhash(200)
        self.nodes[0].invalidateblock(blockhash)
        assert_raises_rpc_error(-8, "Block is not in main chain", self.nodes[0].getchaintxstats, blockhash=blockhash)
        self.nodes[0].reconsiderblock(blockhash)

        chaintxstats = self.nodes[0].getchaintxstats(nblocks=1)
        # 200 txs plus genesis tx
        assert_equal(chaintxstats['txcount'], 201)
        # tx rate should be 1 per 10 minutes, or 1/600
        # we have to round because of binary math
        assert_equal(round(chaintxstats['txrate'] * 600, 10), Decimal(1))

        b1_hash = self.nodes[0].getblockhash(1)
        b1 = self.nodes[0].getblock(b1_hash)
        b200_hash = self.nodes[0].getblockhash(200)
        b200 = self.nodes[0].getblock(b200_hash)
        time_diff = b200['mediantime'] - b1['mediantime']

        chaintxstats = self.nodes[0].getchaintxstats()
        assert_equal(chaintxstats['time'], b200['time'])
        assert_equal(chaintxstats['txcount'], 201)
        assert_equal(chaintxstats['window_final_block_hash'], b200_hash)
        assert_equal(chaintxstats['window_final_block_height'], 200)
        assert_equal(chaintxstats['window_block_count'], 199)
        assert_equal(chaintxstats['window_tx_count'], 199)
        assert_equal(chaintxstats['window_interval'], time_diff)
        assert_equal(round(chaintxstats['txrate'] * time_diff, 10), Decimal(199))

        chaintxstats = self.nodes[0].getchaintxstats(blockhash=b1_hash)
        assert_equal(chaintxstats['time'], b1['time'])
        assert_equal(chaintxstats['txcount'], 2)
        assert_equal(chaintxstats['window_final_block_hash'], b1_hash)
        assert_equal(chaintxstats['window_final_block_height'], 1)
        assert_equal(chaintxstats['window_block_count'], 0)
        assert 'window_tx_count' not in chaintxstats
        assert 'window_interval' not in chaintxstats
        assert 'txrate' not in chaintxstats