def METHOD_NAME(self):
    utxo_count = 90
    utxos = create_confirmed_utxos(self.relayfee, self.nodes[0], utxo_count)
    base_fee = self.relayfee*100 # our transactions are smaller than 100kb
    txids = []
    # Create 3 batches of transactions at 3 different fee rate levels
    range_size = utxo_count // 3
    for i in range(3):
        txids.append([])
        start_range = i * range_size
        end_range = start_range + range_size
        txids[i] = create_lots_of_big_transactions(self.nodes[0], self.txouts, utxos[start_range:end_range], end_range - start_range, (i+1)*base_fee)
    # Make sure that the size of each group of transactions exceeds
    # MAX_BLOCK_BASE_SIZE -- otherwise the test needs to be revised to create
    # more transactions.
    mempool = self.nodes[0].getrawmempool(True)
    sizes = [0, 0, 0]
    for i in range(3):
        for j in txids[i]:
            assert(j in mempool)
            sizes[i] += mempool[j]['size']
        assert(sizes[i] > MAX_BLOCK_BASE_SIZE) # Fail => raise utxo_count
    # add a fee delta to something in the cheapest bucket and make sure it gets mined
    # also check that a different entry in the cheapest bucket is NOT mined (lower
    # the priority to ensure its not mined due to priority)
    self.nodes[0].prioritisetransaction(txids[0][0], 0, int(3*base_fee*COIN))
    self.nodes[0].prioritisetransaction(txids[0][1], -1e15, 0)
    self.nodes[0].generate(1)
    mempool = self.nodes[0].getrawmempool()
    print("Assert that prioritised transaction was mined")
    assert(txids[0][0] not in mempool)
    assert(txids[0][1] in mempool)
    high_fee_tx = None
    for x in txids[2]:
        if x not in mempool:
            high_fee_tx = x
    # Something high-fee should have been mined!
    assert(high_fee_tx != None)
    # Add a prioritisation before a tx is in the mempool (de-prioritising a
    # high-fee transaction so that it's now low fee).
    self.nodes[0].prioritisetransaction(high_fee_tx, -1e15, -int(2*base_fee*COIN))
    # Add everything back to mempool
    self.nodes[0].invalidateblock(self.nodes[0].getbestblockhash())
    # Check to make sure our high fee rate tx is back in the mempool
    mempool = self.nodes[0].getrawmempool()
    assert(high_fee_tx in mempool)
    # Now verify the modified-high feerate transaction isn't mined before
    # the other high fee transactions. Keep mining until our mempool has
    # decreased by all the high fee size that we calculated above.
    while (self.nodes[0].getmempoolinfo()['bytes'] > sizes[0] + sizes[1]):
        self.nodes[0].generate(1)
    # High fee transaction should not have been mined, but other high fee rate
    # transactions should have been.
    mempool = self.nodes[0].getrawmempool()
    print("Assert that de-prioritised transaction is still in mempool")
    assert(high_fee_tx in mempool)
    for x in txids[2]:
        if (x != high_fee_tx):
            assert(x not in mempool)
    # Create a free, low priority transaction.  Should be rejected.
    utxo_list = self.nodes[0].listunspent()
    assert(len(utxo_list) > 0)
    utxo = utxo_list[0]
    inputs = []
    outputs = {}
    inputs.append({"txid" : utxo["txid"], "vout" : utxo["vout"]})
    outputs[self.nodes[0].getnewaddress()] = utxo["amount"] - self.relayfee
    raw_tx = self.nodes[0].createrawtransaction(inputs, outputs)
    tx_hex = self.nodes[0].signrawtransaction(raw_tx)["hex"]
    txid = self.nodes[0].sendrawtransaction(tx_hex)
    # A tx that spends an in-mempool tx has 0 priority, so we can use it to
    # test the effect of using prioritise transaction for mempool acceptance
    inputs = []
    inputs.append({"txid": txid, "vout": 0})
    outputs = {}
    outputs[self.nodes[0].getnewaddress()] = utxo["amount"] - self.relayfee
    raw_tx2 = self.nodes[0].createrawtransaction(inputs, outputs)
    tx2_hex = self.nodes[0].signrawtransaction(raw_tx2)["hex"]
    tx2_id = self.nodes[0].decoderawtransaction(tx2_hex)["txid"]
    try:
        self.nodes[0].sendrawtransaction(tx2_hex)
    except JSONRPCException as exp:
        assert_equal(exp.error['code'], -26) # insufficient fee
        assert(tx2_id not in self.nodes[0].getrawmempool())
    else:
        assert(False)
    # This is a less than 1000-byte transaction, so just set the fee
    # to be the minimum for a 1000 byte transaction and check that it is
    # accepted.
    self.nodes[0].prioritisetransaction(tx2_id, 0, int(self.relayfee*COIN))
    print("Assert that prioritised free transaction is accepted to mempool")
    assert_equal(self.nodes[0].sendrawtransaction(tx2_hex), tx2_id)
    assert(tx2_id in self.nodes[0].getrawmempool())
    # Test that calling prioritisetransaction is sufficient to trigger
    # getblocktemplate to (eventually) return a new block.
    mock_time = int(time.time())
    self.nodes[0].setmocktime(mock_time)
    template = self.nodes[0].getblocktemplate()
    self.nodes[0].prioritisetransaction(txid, 0, -int(self.relayfee*COIN))
    self.nodes[0].setmocktime(mock_time+10)
    new_template = self.nodes[0].getblocktemplate()
    assert(template != new_template)