How to use the ghost-ignition.errors function in ghost-ignition

const express = require('express');
const debug = require('ghost-ignition').debug('app');
const hbs = require('express-hbs');
const multer = require('multer');
const server = require('ghost-ignition').server;
const errors = require('ghost-ignition').errors;
const gscan = require('../lib');
const fs = require('fs-extra');
const logRequest = require('./middlewares/log-request');
const uploadValidation = require('./middlewares/upload-validation');
const ghostVer = require('./ghost-version');
const pkgJson = require('../package.json');
const ghostVersions = require('../lib/utils').versions;
const upload = multer({dest: __dirname + '/uploads/'});
const app = express();
const scanHbs = hbs.create();

// Configure express
app.set('x-powered-by', false);
app.set('query parser', false);

app.engine('hbs', scanHbs.express4({

var _ = require('lodash'),
    util = require('util'),
    errors = require('ghost-ignition').errors;

function GhostError(options) {
    options = options || {};
    this.value = options.value;

    errors.IgnitionError.call(this, options);
}

// jscs:disable
var ghostErrors = {
    DataExportError: function DataExportError(options) {
        GhostError.call(this, _.merge({
            statusCode: 500,
            errorType: 'DataExportError'
        }, options));
    },

// NOTE: this middleware was extracted from Ghost core validation for theme uploads
//       might be useful to unify this logic in the future if it's extracted to separate module
const path = require('path');
const errors = require('ghost-ignition').errors;

const checkFileExists = function checkFileExists(fileData) {
    return !!(fileData.mimetype && fileData.path);
};

const checkFileIsValid = function checkFileIsValid(fileData, types, extensions) {
    const type = fileData.mimetype;

    if (types.includes(type) && extensions.includes(fileData.ext)) {
        return true;
    }

    return false;
};

module.exports = function uploadValidation(req, res, next) {

const concat = require('concat-stream');
const Cookies = require('cookies');
const jwt = require('jsonwebtoken');
const ignition = require('ghost-ignition');

const {
    UnauthorizedError,
    BadRequestError
} = ignition.errors;

const EMPTY = {};
const SIX_MONTHS_MS = 1000 * 60 * 60 * 24 * 184;

const withCookies = (fn, cookieConfig) => (req, res) => {
    return new Promise((resolve) => {
        const cookies = new Cookies(req, res, cookieConfig);
        resolve(fn(req, res, {cookies}));
    });
};

const withBodyAndCookies = (fn, cookieConfig) => (req, res) => {
    return new Promise((resolve, reject) => {
        const cookies = new Cookies(req, res, cookieConfig);
        req.on('error', reject);
        req.pipe(concat(function (buff) {

const errors = require('ghost-ignition').errors,
    util = require('util');

function BookshelfRelationsError(options) {
    options = options || {};

    options.errorType = 'BookshelfRelationsError';
    options.level = 'critical';

    errors.IgnitionError.call(this, options);
}

util.inherits(BookshelfRelationsError, errors.IgnitionError);

module.exports = errors;
module.exports.BookshelfRelationsError = BookshelfRelationsError;

const merge = require('lodash/merge'),
    each = require('lodash/each'),
    util = require('util'),
    errors = require('ghost-ignition').errors;

function GhostError(options) {
    options = options || {};
    this.value = options.value;

    errors.IgnitionError.call(this, options);
}

const ghostErrors = {
    DataExportError: function DataExportError(options) {
        GhostError.call(this, merge({
            statusCode: 500,
            errorType: 'DataExportError'
        }, options));
    },
    DataImportError: function DataImportError(options) {