How to use the ember-resolver.extend function in ember-resolver

/* globals require, requirejs */
import Ember from 'ember';
import Resolver from 'ember-resolver';
import { ROUTES } from './routes';

export default Resolver.extend({
  resolveEngine(parsedName) {
    // TODO: clean this up to use latest ember-resolver from npm
    let engineName = parsedName.fullNameWithoutType;
    let engineModule = engineName + '/engine';

    if (requirejs.entries[engineModule]) {
      let module = require(engineModule);

      return module.default;
    }
  },

  resolveRouteMap(parsedName) {
    let engineName = parsedName.fullNameWithoutType;
    let engineRoutesModule = engineName + '/routes';

// Extensions the ember-resolver lookuppatterns that take a 'packageName'
    function defaultModuleName(packageName, parsedName) {
      return packageName + '/' + this.pluralize(parsedName.type) + '/' + parsedName.fullNameWithoutType;
    }
  ];

// The order is again important
genericModuleNameLookupPatterns.forEach(function(genericLookupPattern) {
  packageNames.concat(config.modulePrefix).forEach(function(packageName) {
    lookupFunctions.push(function(parsedName) {
      return genericLookupPattern.call(this, packageName, parsedName);
    });
  });
});

export default EmberResolver.extend({
  moduleNameLookupPatterns: Ember.computed(function() {
    // Not sure if we need to delegate, this might be enough.
    // return lookupFunctions.concat(this._super());
    return lookupFunctions;
  })
});

import Ember from 'ember';
import EmberResolver from 'ember-resolver';

const MyResolver = EmberResolver.extend({
    pluralizedTypes: {
        sheep: 'sheep'
    }
});

const App = Ember.Application.extend({
    Resolver: MyResolver
});

import Resolver from 'ember-resolver';

export let registry = Object.create(null);
export function setRegistry(newRegistry) {
  registry = newRegistry;
}

export default Resolver.extend({
  resolve(fullName) {
    return registry[fullName] || this._super(...arguments);
  },
});

import Application from '@ember/application';
import EmberResolver from 'ember-resolver';

const MyResolver = EmberResolver.extend({
    pluralizedTypes: {
        sheep: 'sheep'
    }
});

const App = Application.extend({
    Resolver: MyResolver
});

import Resolver from 'ember-resolver';

export let registry = Object.create(null);
export function setRegistry(newRegistry) {
  registry = newRegistry;
}

export default Resolver.extend({
  resolve(fullName) {
    return registry[fullName] || this._super(...arguments);
  },
});