Flow Extension

public class ExtensionName {
    
    Public Flow.Interview.Add_Defenders_to_Quote myAutoFlow { get; set; }
    Public ExtensionName(ApexPages.StandardController controller) {}

	public String getmyID() {
		if (myAutoFlow==null)
 			return '';
		else 
        //Put flow variable that represents the id of newly created record
			return myAutoFlow.vObjID;
		}
	public PageReference getNextPage(){
	PageReference p = new PageReference('/' + getmyID() );
	p.setRedirect(true);
	return p;
	}
}

I'm having trouble create a test class for this extension, so I can't deploy the extension to production.
Do you have a simple test class for this?
Thanks!