got movies_checked_out_count to where it should be working, but need …

…to add searializer to make sure it is working as expected

app/controllers/customers_controller.rb

@@ -2,7 +2,7 @@ class CustomersController < ApplicationController
 def index
   customers = Customer.all
   render(
-    json: customers.as_json(only: [:id, :name, :registered_at, :address, :city, :state, :postal_code, :phone])
+    json: customers.as_json(only: [:id, :name, :registered_at, :address, :city, :state, :postal_code, :phone, :movies_checked_out_count])
   )
 end
 end

app/models/customer.rb

@@ -3,7 +3,7 @@ class Customer < ApplicationRecord
 
   validates :name, presence: true
 
-  def self.movies_checked_out
+  def movies_checked_out_count
     self.rentals.where(checked_out: true).count
   end # movies_checked_out