interface IWhitelist {
  /// @dev Emitted when a contract is added to the whitelist.
  ///
  /// @param account The account that was added to the whitelist.
  event AccountAdded(address account);

  /// @dev Emitted when a contract is removed from the whitelist.
  ///
  /// @param account The account that was removed from the whitelist.
  event AccountRemoved(address account);

  /// @dev Emitted when the whitelist is deactivated.
  event WhitelistDisabled();

  /// @dev Returns the list of addresses that are whitelisted for the given contract address.
  ///
  /// @return addresses The addresses that are whitelisted to interact with the given contract.
  function getAddresses() external view returns (address[] memory addresses);

  /// @dev Returns the disabled status of a given whitelist.
  ///
  /// @return disabled A flag denoting if the given whitelist is disabled.
  function disabled() external view returns (bool);

  /// @dev Adds an contract to the whitelist.
  ///
  /// @param caller The address to add to the whitelist.
  function add(address caller) external;

  /// @dev Adds a contract to the whitelist.
  ///
  /// @param caller The address to remove from the whitelist.
  function remove(address caller) external;

  /// @dev Disables the whitelist of the target whitelisted contract.
  ///
  /// This can only occur once. Once the whitelist is disabled, then it cannot be reenabled.
  function disable() external;

  /// @dev Checks that the `msg.sender` is whitelisted when it is not an EOA.
  ///
  /// @param account The account to check.
  ///
  /// @return whitelisted A flag denoting if the given account is whitelisted.
  function isWhitelisted(address account) external view returns (bool);
}
/// @title  Whitelist
/// @author Alchemix Finance
function disable() external;
/// @dev Disables the whitelist of the target whitelisted contract.
///
/// This can only occur once. Once the whitelist is disabled, then it cannot be reenabled.