l81-l85
// closeFactorMantissa must be strictly greater than this value
uint internal constant closeFactorMinMantissa = 0.05e18; // 0.05

// closeFactorMantissa must not exceed this value
uint internal constant closeFactorMaxMantissa = 0.9e18; // 0.9
l850-l859
function _setCloseFactor(uint newCloseFactorMantissa) external returns (uint) {
    // Check caller is admin
    require(msg.sender == admin, "only admin can set close factor");

    uint oldCloseFactorMantissa = closeFactorMantissa;
    closeFactorMantissa = newCloseFactorMantissa;
    emit NewCloseFactor(oldCloseFactorMantissa, closeFactorMantissa);

    return uint(Error.NO_ERROR);
}
