I am trying to instantiate my controller in my test class but I had to do the controller class slightly differently then others that I've done in the past and so I can't figure out how to get it define in the test class.

My controllerclass  says this for the page controller

private Id demoId;

    private ApexPages.StandardController controller;

    public DemoContactEntryExtension(ApexPages.StandardController controller) {
        this.controller = controller;

        // get the id of the demo
        demoId = controller.getId();

my test class says this:

//Create Test Data

Account a=new Account(Name='Test Account');
    insert a;
Contact c = new Contact(FirstName='John',LastName='Doe', AccountID=a.id);
    insert c;
Opportunity o = new Opportunity(Name='Test Opportunity',closedate=system.today(), stagename='Confirmed Teaching/Class Schedule',Probability=0.95, accountID=a.id);
    insert o;      
OpportunityContactRole ocr = new OpportunityContactRole (Opportunityid = o.id, Contactid=c.id, role='Decision Maker', isPrimary=True) ;     
    insert ocr;  
Demo__c demo = new Demo__c (Primary_Opportunity__c=o.id, Name='Test Demo');
    insert demo;
Demo_Opportunity__c doc = new Demo_Opportunity__c (Opportunity__c=o.id, Demo__c=demo.id);
    insert doc;
Demo_Contact__c dcc = new Demo_Contact__c (Contact__c=c.id, demo__c=demo.id);
    insert dcc;

     
        ////////////////////////////////////////
        //  test DemoContactEntry
        ////////////////////////////////////////
        
           // load the page             
        PageReference pageRef = Page.Demo_Contact_Entry;
        pageRef.getParameters().put('Id',dcc.demo__c);
        Test.setCurrentPageReference(pageRef);
    // load the extension
        
        DemoContactEntryExtension dCEE = new DemoContactEntryExtension(new ApexPages.StandardController(dcc.demo__c));
        

If anyone knows how I can change this to instantiate the controller that would be great.

Thanks,

Amanda