Calling future from future

.java

public class AccountTriggerHelper {
  // function being called at before insert
    public static void beforeInsert() {
        for (Account a: (List < Account > ) Trigger.new) {
            a.accountNumber = '123456678';
        }
       
    }
  // function being called at after insert 
    public static void afterInsert() {
        List < Id > accountId = new List < Id > ();
        for (Account a: (List < Account > ) Trigger.new) {
            accountId.add(a.Id);
        }
        future1(accountId);
    }
  // future method which takes accountid as parameters and insert a contact for those accounts
    @future
    public static void future1(List < Id > accountId) {
      System.debug('In future method 1');
        List < Contact > con = new List < Contact > ();
        for (Id a: accountId) {
            con.add(new Contact(accountId = a, firstname = 'In future', lastName = 'Created'));
        }
        insert con;
// If you remove below future method call it will create new contact record
      future2();
    }
  // another future method
    @future
    public static void future2() {
        System.debug('I am inside future method2');
    }
}