I have been trying to get this test for this controller extension to work and I am not having any luck whatsoever.  Can someone look at the test code and see why i keep getting "Constructor not defined: [ApexPages.StandardController].<Constructor>(Id)"

I am very new to VF pages.  Thank you.

Controller
 

public class DesignationEditorController {
	/*
		Controller Notes:
			Standard override for Add and Save need to exist as list opens and remains in edit mode
	*/

	public List<SE_Designation__c> Designations { get; set; }
	private final Discovery__c ParentDiscovery;
	public String Blurb { get; set; }
 
	//used to get a hold of the record selected for deletion
	public string SelectedDeleteId { get; set; }

	public DesignationEditorController(ApexPages.StandardController stdController) 
	{
		this.ParentDiscovery = (Discovery__c) stdController.getRecord();
		refreshDesignations();                
	}
  
  
	// See 'Controller Notes:' above
	public void Add()
	{
		// Prevent Multiple Blank Records adds
		refreshDesignations();
		boolean goodDesignation = true;
		for(SE_Designation__c d: Designations)
		{
			if(goodDesignation == true && d.Dest_Position__c == Null)
				goodDesignation = false;
		}
		// only add if no blank Dest_Position__c
		if(goodDesignation == true) 
		{
			SE_Designation__c newDes = initNewDesignation();
			insert newDes;
			refreshDesignations();
		}
	}
    
	// See 'Controller Notes:' above
	public void Save() 
	{    
		doSave();
		return;
	}
  
	private void doSave() 
	{
		update Designations;    
	}

	private SE_Designation__c initNewDesignation() 
	{
		SE_Designation__c d = new SE_Designation__c();
		d.Discovery__c = ParentDiscovery.Id;
		d.Name = 'New';
		return d;
	}
  
	private void refreshDesignations() 
	{
		Designations  = [SELECT Id,Dest_Position__c,Dest_Time_Line__c,Dest_Pri_Power_Prod_pick__c,Dest_Pri_Receptacle__c,
			Dest_Red_Power_Prod_pick__c,Dest_Red_Receptacle__c,Dest_DC_Product_pick__c,Dest_V_Drop__c,Dest_DC_Lug__c,Dest_DC_Term__c,
			Dest_Cabinet_Footprint__c, Dest_DEMARC__c, Dest_Weight__c, Dest_Cab_Notes__c FROM SE_Designation__c
			WHERE Discovery__c = :ParentDiscovery.Id
			ORDER BY LastModifiedDate ASC NULLS FIRST
			];    
	} 
   

	// See 'Controller Notes:' above
	public void DeleteDesignation() 
	{
		// if for any reason we are missing the reference
		if (SelectedDeleteId == null)     
			return;

		// find the record within the collection
		SE_Designation__c tobeDeleted = null;
    
		for(SE_Designation__c d : Designations)
			if (d.Id == SelectedDeleteId) 
			{
				tobeDeleted = d;
				break;
			}

		//if record found delete it
		if (tobeDeleted != null) 
		{
			delete tobeDeleted;
		}
    
		//refresh the data
		refreshDesignations();
	}

}

Visual Force Page
 

<apex:page showHeader="false" standardController="Discovery__c" extensions="DesignationEditorController">
    <apex:form id="form" > 
        <apex:pageBlock >
            <apex:pageBlockButtons >
                <apex:commandButton action="{!Save}" value="Save"/> 
                <apex:commandButton action="{!Add}" value="New Designation"/>
               <!--  <apex:commandButton action="{!Add}" onclick="javascript:NewDesignation();" value="New Designation"/>  -->
            </apex:pageBlockButtons>
            <apex:pageBlockTable value="{!Designations}" var="designation">

            <apex:column >
            <a href="javascript:DeleteDesignation('{!designation.Id}');" style="font-weight:bold">Del</a>
            </apex:column>

                <apex:column headerValue="Rack"><apex:inputField value="{!designation.Dest_Position__c}"/></apex:column>
                <apex:column headerValue="Timeline"><apex:inputField value="{!designation.Dest_Time_Line__c}"/></apex:column>
                <apex:column headerValue="Prim Power Prod"><apex:inputField value="{!designation.Dest_Pri_Power_Prod_pick__c}"/></apex:column>
                <apex:column headerValue="Prim Power Recep"><apex:inputField value="{!designation.Dest_Pri_Receptacle__c}"/></apex:column>
                <apex:column headerValue="Redun Power Prod"><apex:inputField value="{!designation.Dest_Red_Power_Prod_pick__c}"/></apex:column>
                <apex:column headerValue="Redun Power Recep"><apex:inputField value="{!designation.Dest_Red_Receptacle__c}"/></apex:column>
                <apex:column headerValue="DC Product"><apex:inputField value="{!designation.Dest_DC_Product_pick__c}"/></apex:column>
                <apex:column headerValue="V Drop"><apex:inputField value="{!designation.Dest_V_Drop__c}"/></apex:column>
                <apex:column headerValue="DC Lug"><apex:inputField value="{!designation.Dest_DC_Lug__c}"/></apex:column>
                <apex:column headerValue="DC Term"><apex:inputField value="{!designation.Dest_DC_Term__c}"/></apex:column>
                <apex:column headerValue="Cab Size"><apex:inputField value="{!designation.Dest_Cabinet_Footprint__c}"/></apex:column>
                <apex:column headerValue="DEMARC"><apex:inputField value="{!designation.Dest_DEMARC__c}"/></apex:column>
                <apex:column headerValue="Weight"><apex:inputField value="{!designation.Dest_Weight__c}"/></apex:column>
                <apex:column headerValue="Cab Notes"><apex:inputField value="{!designation.Dest_Cab_Notes__c}"/></apex:column>
            </apex:pageBlockTable>
        </apex:pageBlock>
        <apex:actionFunction action="{!DeleteDesignation}" name="DeleteDesignation" reRender="form" >
            <apex:param name="accountid" value="" assignTo="{!SelectedDeleteId}"/>
        </apex:actionFunction>
        <apex:actionFunction action="{!Add}" name="NewDesignation" reRender="form" >
        </apex:actionFunction>
    </apex:form>
</apex:page>

Test Code
 

@isTest(SeeAllData=false)
private class DesignationEditorControllerTest {
    static testMethod void DesignationEditorControllerTestMethod() {
    	// Prepare VF page 
		PageReference pageRef = Page.SE_Designation_Section;
		Test.setCurrentPage(pageRef);

		// Get any Discovery and populate Controller
		
		Discovery__c d = new Discovery__c([Select Id From Discovery__c Limit 1]);
		ApexPages.StandardController sc = new ApexPages.StandardController(d);

		//list<Discovery__c> d = [Select Id From Discovery__c Limit 1];
		//ApexPages.StandardController sc = new ApexPages.StandardController(d.get(0));

		// Intialize controller
		DesignationEditorController controller = new DesignationEditorController();

		// Add page parameters for required field
		 ApexPages.currentPage().getParameters().put('Rack', 'Test Rack');
		
		// Test methods
		controller.Add();
		controller.Save();
		controller.DeleteDesignation();

    }
}