{
  use warnings;
  # warnings are enabled here
}
# warnings are not enabled here

##</code><code>##

package Foo;

{
  use Carp "croak";
  # croak works here

  {
    package Bar;
    # croak does not work here
  }

  # croak works here again
}

# croak still works here

##</code><code>##

{
  package Foo;
  use Person;
}

{
  package Bar;
  my $bob = Person::->new;
}