human
Solve the following python programming problem given the following code:
@ patch ('mock.patch.TEST_PREFIX', 'foo') 
def test_patch_test_prefix(self) : 
    class Foo (object) : 
        thing = 'original' 
        def foo_one(self) : 
            return self.thing 
def foo_two(self) : 
            return self.thing 
def test_one(self) : 
            return self.thing 
def test_two(self) : 
            return self.thing 
Foo = patch.object (Foo, 'thing', 'changed') (foo) 
    foo = Foo () 
    self.assertEqual (foo.foo_one (), 'changed') 
    self.assertEqual (foo.foo_two (), 'changed') 
    self.assertEqual (foo.test_one (), 'original') 
    self.assertEqual (foo.test_two (), 'original') 

    
    

    Fix the buggy line: Foo = patch.object (Foo, 'thing', 'changed') (foo)
assistant
#Here is Python code to fix the buggy line: Foo = patch.

Foo = patch.object (Foo, 'thing', 'changed') (Foo)