The reference code used in running performance metrics for loops

Performance Measuring Apex Loops

public with sharing class PreferencesManager {

	//public static Account setEmailPreferences(Account acc, Boolean preference) {
	//	for(Integer i = 0; i < acc.Contacts.size(); i++) {
	//		acc.Contacts[i].Email_Preference__c = preference;
	//	}
	//	return acc;
	//}
	//2374
	

	//public static Account setEmailPreferences(Account acc, Boolean preference) {

	//	for(Integer i = 0, j = acc.Contacts.size(); i < j; i++) {
	//		acc.Contacts[i].Email_Preference__c = preference;
	//	}
	//	return acc;
	//}
	////1350


	//public static List<Contact> setEmailPreferences(Account acc, Boolean preference) {
		
	//	List<Contact> contacts = acc.Contacts;

	//	for(Integer i = 0, j = contacts.size(); i < j; i++) {
	//		contacts[i].Email_Preference__c = preference;
	//	}
	//	return contacts;
	//}
	//210

	//Steven Herod - @sherod
	public static List<Contact> setEmailPreferences(Account acc, Boolean preference) {
		
		List<Contact> contacts = acc.Contacts;

		for(Contact con : contacts) {
			con.Email_Preference__c = preference;
		}
		return contacts;
	}

	//Andy Mahood - @andymahood__c (Query timed at 84 ms)
	//public static void setEmailPreferences(Boolean preference) {

	//	for(Contact con : [SELECT Id, Email_Preference__c FROM Contact WHERE Account.Name = 'sForce']) {
	//		con.Email_Preference__c = preference;
	//	}
	//}

	//Andrew Fawcett - @andyinthecloud
	//public static List<Contact> setEmailPreferences(Account acc, Boolean preference) {
		
	//	ContactIterator iterator = new ContactIterator(acc.Contacts);

	//	while(iterator.hasNext()) {
	//		iterator.next().Email_Preference__c = preference;
	//	}
	//	return iterator.contacts;
	//}

	public with sharing class ContactIterator implements Iterator<Contact> {

		public List<Contact> contacts;
		private Integer contactsSize;
		private Integer currentIndex = 0;

		public ContactIterator(List<Contact> cons) {
			contacts = cons;
			contactsSize = contacts.size();
		}

		public Boolean hasNext() {
			return currentIndex < contactsSize;
		}

		public Contact next() {
			Contact currentCon = contacts[currentIndex];
			currentIndex++;
			return currentCon;
		}
	}

}