My job is to fill the `__` below (what is equal to `self.my_method...`). 

```
def my_method_in_the_same_class(a, b)
  a * b
end

def test_calling_methods_in_same_class_with_explicit_receiver
  assert_equal __, self.my_method_in_the_same_class(3,4)
end

```

I get `NoMethodError: private method 'my_method_in_the_same_class' called for main:Object`. The correct answer is 12 and I don't know why I get this error. I can just type 12, but I guess that's not the point of learning.