9 has one => (is => 'ro');
10 has two => (is => 'rw', init_arg => undef);
11 has three => (is => 'ro', init_arg => 'THREE', required => 1);
17 has four => (is => 'ro');
27 has five => (is => 'rw');
36 { %$foo }, { one => 1, three => 3 }, 'simple class ok'
47 { %$baz }, { one => 1, three => 3, four => 4, five => 5 },
48 'subclass with role ok'