3 Types of Actions

// Effect Action Types Example
 @Effect()
 insert: Observable<Action> = this.actions$.pipe(
   ofType<InsertUser>(UserActionTypes.InsertUser), // command
   exhaustMap(action =>
     this.service.create(action.payload.user).pipe(
       map((user: User) => new InsertUserSuccess({ result: user })), // document
       catchError(() => of(new UserActionFail(
		{ error: 'Error inserting user.' }))) // event
     )
   )
 );