Create an Apex class that uses the @future annotation to update Account records.

Create an Apex class with a future method that accepts a List of Account IDs and updates a custom field on the Account object with the number of contacts associated to the Account. Write unit tests that achieve $100\%$ code coverage for the class. Every hands$-$on challenge in this module asks you to create a test class.

Create a field on the Account object:

Label: Number Of Contacts

Name: Number$\_$Of$\_$Contacts

Type: Number

This field will hold the total number of Contacts for the Account

Create an Apex class:

Name: AccountProcessor

Method name: countContacts

The method must accept a List of Account IDs

The method must use the @future annotation

The method counts the number of Contact records associated to each Account ID passed to the method and updates the 'Number$\_$Of$\_$Contacts$\_\_$c$\text{'}$ field with this value

Create an Apex test class:

Name: AccountProcessorTest

The unit tests must cover all lines of code included in the AccountProcessor class, resulting in $100\%$ code coverage.

Before verifying this challenge, run your test class at least once using the Developer Console Run All feature