A message handler is a PHP callable, the recommended way to create it is tocreate a class that has the AsMessageHandlerattribute and has an __invoke() method that's type-hinted with themessage class (or a message interface):
A message handler is a PHP callable, the recommended way to create it is tocreate a class that has the AsMessageHandlerattribute and has an __invoke() method that's type-hinted with themessage class (or a message interface):