message: Remove unused code and imports
diff: -import camelcaseKeys = require('camelcase-keys');
  -import { cloneDeep } from 'lodash';
  -import mmdb = require('maxmind');
  -import * as anonymousIPFixture from '../fixtures/anonymous-ip.json';
  -import * as connectionTypeFixture from '../fixtures/geoip2-connection-type.json';
  -import * as domainFixture from '../fixtures/geoip2-domain.json';
  -import * as ispFixture from '../fixtures/geoip2-isp.json';
  -import * as geoip2Fixture from '../fixtures/geoip2.json';
  -import * as asnFixture from '../fixtures/geolite2-asn.json';
  import { AddressNotFoundError, BadMethodCallError, ValueError } from './errors';
  import Reader from './reader';
  -import ReaderModel from './readerModel';
  -
  -const ips = {
  - empty: '88.88.88.88',
  - invalid: 'foobar',
  - notFound: '99.99.99.99',
  - valid: '11.11.11.11',
  -};
  -
  -const networks = {
  - empty: '88.88.88.88/32',
  - valid: '11.11.11.0/24',
  -};
  -
  -const createMmdbReaderMock: any = (databaseType: string, fixture: any) => ({
  - getWithPrefixLength(ipAddress: string) {
  - if (ipAddress === ips.notFound) {
  - throw new Error('ip address not found');
  - }
  -
  - if (ipAddress === ips.empty) {
  - return [{}, 32];
  - }
  - return [fixture, 24];
  - },
  - metadata: {
  - binaryFormatMajorVersion: 1,
  - binaryFormatMinorVersion: 2,
  - buildEpoch: new Date(),
  - databaseType,
  - description: 'hello',
  - ipVersion: 5,
  - languages: ['en'],
  - nodeByteSize: 1,
  - nodeCount: 1,
  - recordSize: 1,
  - searchTreeSize: 1,
  - treeDepth: 1,
  - },
  -});
  describe('ReaderModel', () => {
  describe('city()', () => {
  