def METHOD_NAME(w3, market_maker, erc20):
    a1 = w3.eth.accounts[1]
    erc20.approve(market_maker.address, w3.to_wei(2, "ether"), transact={})
    market_maker.initiate(
        erc20.address, w3.to_wei(1, "ether"), transact={"value": w3.to_wei(2, "ether")}
    )
    assert erc20.balanceOf(market_maker.address) == w3.to_wei(1, "ether")
    assert erc20.balanceOf(a1) == 0
    assert market_maker.totalTokenQty() == w3.to_wei(1, "ether")
    assert market_maker.totalEthQty() == w3.to_wei(2, "ether")
    market_maker.ethToTokens(transact={"value": 100, "from": a1})
    assert erc20.balanceOf(market_maker.address) == 999999999999999950
    assert erc20.balanceOf(a1) == 50
    assert market_maker.totalTokenQty() == 999999999999999950
    assert market_maker.totalEthQty() == 2000000000000000100