While updating a test method I received the error mentioned in this subject. I am not sure where the offendor lies so can anyone assist, I have attached the code to give a better picture.

/**
 * This class contains unit tests for validating the behavior of Apex classes
 * and triggers.
 *
 * Unit tests are class methods that verify whether a particular piece
 * of code is working properly. Unit test methods take no arguments,
 * commit no data to the database, and are flagged with the testMethod
 * keyword in the method definition.
 *
 * All test methods in an organization are executed whenever Apex code is deployed
 * to a production organization to confirm correctness, ensure code
 * coverage, and prevent regressions. All Apex classes are
 * required to have at least 75% code coverage in order to be deployed
 * to a production organization. In addition, all triggers must have some code coverage.
 * 
 * The @isTest class annotation indicates this class only contains test
 * methods. Classes defined with the @isTest annotation do not count against
 * the organization size limit for all Apex scripts.
 *
 * See the Apex Language Reference for more information about Testing and Code Coverage.
 */
@isTest
private class TestProdCase {

    static testMethod void myUnitTest() {
  	test.startTest();
	
	/**
	creating a list to iterate through both states of an Opportunity Case (Submitter, Vendor)
	**/
	List<Integer> run = new List<Integer>();
	run.add(1);
	run.add(2);
	run.add(3);
	for(Integer it=0;it <run.size(); it++){
	
	System.debug('Alerting on ----> '+run);
// 	List<RecordType> rec = [Select id from RecordType where name in ('Implementation Vendor','Implementation Submitter')];
// 	for(Integer it = 0;it<rec.size();it++){

    	

    /**
    Create Account Record
    **/	
 
    	Account a = new Account(Name='TestAccount');
    	insert a;
   	
   	/**
    Create Contact Record
    **/		
	  String acId = null;
      List<Account> ac = [Select id from Account where name = 'TestAccount'];
	  Contact c = new Contact(FirstName='Johnny', LastName='Tester', AccountId=ac[0].Id);
	  acId = ac[0].id;
	  insert c;
	  System.debug('Alerting on ----> '+c);

	
    
    /**
    Create Opportunity Record
    **/	
    System.debug('Alerting on ----> '+'Going into the Opportuntiy creation');
    Opportunity o = new Opportunity();
    list<Contact> co = [Select Id from Contact where firstName='Johnny' and lastName = 'Tester'];
   
   		Integer ct = co.size();
   		System.debug('Alerting on ----> '+ct);
		o.Name='TestOpportunity';
		o.CloseDate=Date.today();
		o.StageName='Prospecting';
		o.Opportunity_States__c='AL';
		o.Status__c='Business Development';
		o.AccountId=a.Id;
		o.Name='TestOpportunity';
		o.CloseDate=Date.today();
		system.debug('Alerting on ----> '+co);
		o.Implementation_Contac__c=co[0].Id;
		
		//Sets the Opportunity type to vendor or submitter
		if(it == 1){
			o.Type='Submitter';
		}else if (it == 2){
			o.Type='Vendor';
		}else{
		o.Type='Receiver';
		}

		

		insert o;	
		System.debug('Opportunity Object '+ o);	
	/*
	Set the Product
	*/
	List<PricebookEntry> numb = [Select Id, Pricebook2Id from PricebookEntry where isActive = TRUE LIMIT 5];
	//OpportunityLineItem opl = new OpportunityLineItem(OpportunityId=o.Id);
	for(Integer i = 0;i<numb.size(); i++){
		OpportunityLineItem opl = new OpportunityLineItem(OpportunityId=o.Id);
//		opl.PricebookEntryId=numb[i].Id;
		opl.PricebookEntryId=numb[i].Id;
		opl.Quantity=25;
		opl.ServiceDate=Date.today();
		opl.UnitPrice=125.50;
		insert opl;
	}
	String opp = o.Id;
	
	/*
	Pass in the Opportunity Object
	*/
	ProdCase testing = new ProdCase(o);

	/*
	Pass  in the Opportunity ID
	*/
	testing.prodDetails(opp);
	//test.stopTest();
		}
		test.stopTest();
    }
}