We have been using ES2015 imports extensively throughout this chapter already, but let's emphasize when that was. As mentioned, all constructs used ES2015 modules, models, services, components, and modules. For the module, this looked like this:

import { NgModule } from '@angular/core';

@NgModule({
  declarations: [],
  imports: [],
  exports: [],
  providers: []
})
export class FeatureModule {}

Here, we see that we import the functionality we need and we end up exporting this class, thereby making it available for other constructs to consume. It's the same thing with modules, like so:

import { Component } from '@angular/core';

@Component({
  selector: 'example'
})
export class ExampleComponent {}

The pipe, directive, and filter all follow the same pattern of importing what they need and exporting themselves to be included as part of an NgModule.