function deposit(uint256 _pid, uint256 _amount)
    external
    whenNotPaused
    nonReentrant
{
    _checkpoint(_pid, msg.sender);
    deposits[_pid][msg.sender].epoch = currentEpoch();
    deposits[_pid][msg.sender].amount += uint192(_amount);
    if (_amount > 0) {
        IERC20 lpToken = IERC20(
            IRewardStaking(convexPool[_pid]).poolInfo(_pid).lptoken
        );

        lpToken.safeTransferFrom(msg.sender, address(this), _amount);
        lpToken.safeApprove(convexBooster, _amount);
        IConvexDeposits(convexBooster).deposit(_pid, _amount, true);
        lpToken.safeApprove(convexBooster, 0);
        uint256 pid = masterChef.pid(address(lpToken));
        masterChef.deposit(msg.sender, pid, _amount);
    }

    emit Deposited(msg.sender, _amount);
}
require(_amount <= type(uint192).max, "...");
