human
Solve the following python programming problem given the following code:
def get_pushes(self) : 
    pushes = [None] 
    def on_select_return(success, db_results) : 
        assert success 
        pushes [0] = db_results.fetchall () 
db.execute_cb (db.push_pushes.select (), <MASK>) 
    return pushes [0] 
    
    Given the code above, what is a proper replacement for <MASK>?
assistant
#Here is a proper replacement for <MASK>.
def on_select_return(