old_contents: 'use strict';
  
  const errorHierarchy = {
      'BaseError': {
          'ExchangeError': {
              'AuthenticationError': {
                  'PermissionDenied': {},
                  'AccountSuspended': {},
              },
              'ArgumentsRequired': {},
              'BadRequest': {
                  'BadSymbol': {},
              },
              'BadResponse': {
                  'NullResponse': {},
              },
              'InsufficientFunds': {},
              'InvalidAddress': {
                  'AddressPending': {},
              },
              'InvalidOrder': {
                  'OrderNotFound': {},
                  'OrderNotCached': {},
                  'CancelPending': {},
                  'OrderImmediatelyFillable': {},
                  'OrderNotFillable': {},
                  'DuplicateOrderId': {},
              },
              'MaintananceError': {},
              'NotSupported': {},
          },
          'NetworkError': {
              'DDoSProtection': {},
              'ExchangeNotAvailable': {},
              'InvalidNonce': {},
              'RequestTimeout': {},
          },
      },
  };
  
  module.exports = errorHierarchy;
  
new_contents: 'use strict';
  
  const errorHierarchy = {
      'BaseError': {
          'ExchangeError': {
              'AuthenticationError': {
                  'PermissionDenied': {},
                  'AccountSuspended': {},
              },
              'ArgumentsRequired': {},
              'BadRequest': {
                  'BadSymbol': {},
              },
              'BadResponse': {
                  'NullResponse': {},
              },
              'InsufficientFunds': {},
              'InvalidAddress': {
                  'AddressPending': {},
              },
              'InvalidOrder': {
                  'OrderNotFound': {},
                  'OrderNotCached': {},
                  'CancelPending': {},
                  'OrderImmediatelyFillable': {},
                  'OrderNotFillable': {},
                  'DuplicateOrderId': {},
              },
              'NotSupported': {},
          },
          'NetworkError': {
              'DDoSProtection': {},
              'ExchangeNotAvailable': {
                  'OnMaintenance': {},
              },
              'InvalidNonce': {},
              'RequestTimeout': {},
          },
      },
  };
  
  module.exports = errorHierarchy;
  
subject: Update errorHierarchy.js