public static void TestMethod(this ITestable item, string testString)
 {
     if (testString == "blue")
     {
         item.RunA();
     }
     else if (testString == "red")
     {
         item.RunB();
     }
     else if (testString == "orange")
     {
         item.RunA();
     }
     else if (testString == "pink")
     {
         item.RunB();
     }
 }