How can you redefine a variable when inheriting a class in puppet?

Question

Puppet

I want to write the following construction:
class classA {
$a = "AAA"
notify { $a : }
}
class classB inherits classA {
$a = "BBB"
}
Calling
class { classB : } from the node, I
expect to see BBB in notifications, but pappet stubbornly shoves
Notice: AAA
Notice: /Stage[main]/Classa/Notify[AAA]/message: defined 'message' as 'AAA'
How to get BBB as output?

Answer 1

solution:
class classB inherits classA {
$a = "BBB"
notify { [AAA] : message => $a }
}