https://rt.cpan.org/Ticket/Display.html?id=69237
is => 'rw',
isa => 'Foo',
);
+ has bar => (
+ is => 'rw',
+
+ lazy => 1,
+ default => sub { 42 },
+ );
package Foo;
use Mouse;
$x->foo(Foo->new(value => 20));
is $x->foo->value, 20;
+
+ is $x->bar, 42, 'callback for default';
})->join();
is $o->foo->value, 42;