human
Solve the following python programming problem given the following code:
def contains_rewrite(node, name, expr, assumed_result) : 
    '
    Takes an AST tree (node), and an expression with its
    name. Returns a new AST tree with the expr taking the
    assumed_result value, with potential optimizations.
    ' 
    expr_set = expr.left.value 
    def replace_func(pattern, node) : 
        if (assumed_result is True) : 
            set_prime = (node.left.value & expr_set) 
            if (set_prime == expr_set) : 
                return ast.Constant (True) 
else : 
                if (len (set_prime) == 0) : 
                    return ast.Constant (False) 
set_prime_diff = (expr_set - node.left.value) 
            if (len (set_prime_diff) < len (set_prime)) : 
                node.left.value = set_prime_diff 
                return ast.NegateOperator (node) 
else : 
            set_prime = (node.left.value - expr_set) 
            if (len (set_prime) == 0) : 
                return ast.Constant (False) 
node.left.value = set_prime 
        return None 
pattern = SimplePattern ('types:ContainsOperator', 'types:LiteralSet', ASTPattern (expr.right)) 
    return tile (node, [pattern], node) 

    
    

    Fix the buggy line: return tile (node, [pattern], node)
assistant
#Here is Python code to fix the buggy line: return tile (node, [pattern], node)
.

return tile (node, [pattern], def replace_func()