Interface Casting in C#

interface ITest{}
 
class MyClass{}
 
class Main {
     public static void main(String[] args) 
     {
         MyClass obj = new MyClass();
 
         ITest iObj = (ITest)obj;  //compiles fine --Line 2
         
         SomeMethod(obj);          // compile time error --Line 3
                   //you have pass obj rather than Iobj
                        // try this SomeMethod(IObj);
     }
 
     public static void SomeMethod(ITest test) {}
 
}