interface ICollateralManager
{
  function isSufficientInitialCollateral(address lendingToken, uint256 principal, address collateralToken, uint256 collateralAmount) external view returns (bool);

  // returns (bool isSufficient, uint collateralRatio%);
  function isSufficientCollateral(address borrower, address lendingToken, uint256 principal, address collateralToken, uint256 collateralAmount) external view returns (bool, uint256);
}
function isSufficientCollateral(address borrower, address lendingToken, uint256 principal, address collateralToken, uint256 collateralAmount) external view returns (bool, uint256);

// returns (bool isSufficient, uint collateralRatio%);