Call a delegate event from unit test

See more:

testing

Issue:
When I run the unit test application I receive the following error
"
Test method KT_TestProject.UnitTest1.Load_ProductsTest_Pass threw exception: System.MissingMethodException: Method 'ASP.default_aspx.Button2_Click' not found..
"

Code:
Application:

protected void Page_Load(object sender, EventArgs e)
       {
           Button2.Click += Button2_Click;
       }

void Button2_Click(object sender, EventArgs e)
       {
           TextBox2.Text = TextBox1.Text;
       }

Unit Test:

[TestMethod]
        [HostType("ASP.NET")]
        [UrlToTest("http://localhost/Sample/Default.aspx")]        
        public void Load_Pass()
        {  
Page page = testContextInstance.RequestedPage;
            PrivateObject po = new PrivateObject(page);
po.Invoke("Button2_Click", page, EventArgs.Empty);
Assert.Inconclusive("Doesnot return anything");

}