human
Solve the following python programming problem given the following code:
def test_read_only(self) : 
    a = DBRef ('coll', ObjectId ()) 
    def foo() : 
        a.collection = 'blah' 
def bar() : 
        a.id = 'aoeu' 
self.assertEqual ('coll', foo.collection) 
    a.id 
    self.assertEqual (None, a.database) 
    self.assertRaises (AttributeError, foo) 
    self.assertRaises (AttributeError, bar) 

    
    

    Fix the buggy line: self.assertEqual ('coll', foo.collection)
assistant
#Here is Python program to fix the buggy line: self.

self.assertEqual ('coll', a.collection)