11.5.5 Cannot use blocking in an interface

Event handling can be ’blocking’ in component behavior only. It is not allowed in interfaces. So:

interface blocking_in_interface
{
  in void hello ();
  behavior
  {
    blocking on hello:;
  }
}

This results in the following error message:

blocking-in-interface.dzn:6:5: error: cannot use blocking in an
    interface