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// Returns the amount of Token2 that the user will get when swapping a given amount of Token1 for Token2
function getSwapToken2Estimate(uint256 _amountToken2) public view activePool returns(uint256 amountToken1) {
    uint256 token2After = totalToken2.add(_amountToken2);
    uint256 token1After = K.div(token2After);
    amountToken1 = totalToken1.sub(token1After);

// To ensure that Token1's pool is not completely depleted leading to inf:0 ratio
    if(amountToken1 == totalToken1) amountToken1--;
}

// Returns the amount of Token2 that the user should swap to get _amountToken1 in return
function getSwapToken2EstimateGivenToken1(uint256 _amountToken1) public view activePool returns(uint256 amountToken2) {
    require(_amountToken1 < totalToken1, "Insufficient pool balance");
    uint256 token1After = totalToken1.sub(_amountToken1);
    uint256 token2After = K.div(token1After);
    amountToken2 = token2After.sub(totalToken2);
}

// Swaps given amount of Token2 to Token1 using algorithmic price determination
function swapToken2(uint256 _amountToken2) external activePool validAmountCheck(token2Balance, _amountToken2) returns(uint256 amountToken1) {
    amountToken1 = getSwapToken2Estimate(_amountToken2);

token2Balance[msg.sender] -= _amountToken2;
    totalToken2 += _amountToken2;
    totalToken1 -= amountToken1;
    token1Balance[msg.sender] += amountToken1;
}