ManagedLeveragedVault::donateCollateral() is missing a slippage check

function donateCollateral(uint256 _collateralAmount, address _upperHint, address _lowerHint) external onlyOwner {
    BoycoVaultStorage storage b$ = _getBoycoVaultStorage();

    uint256 assetsNeeded = b$.collVault.previewMint(_collateralAmount);
    IERC20(asset()).transferFrom(msg.sender, address(this), assetsNeeded);

    IERC20(asset()).forceApprove(address(b$.collVault), assetsNeeded);
    b$.collVault.mint(_collateralAmount, address(this));

    IERC20(address(b$.collVault)).forceApprove(address(b$.borrowerOperations), _collateralAmount);
    _addColl(_collateralAmount, _upperHint, _lowerHint);

    // TODO consider invariants
}