{	package Foo;
	sub foo {}
}
{	package Bar;
	use parent -norequire, 'Foo';
	sub bar {};
}

print Foo->can('foo')//'undef', "\n";
print Foo->can('bar')//'undef', "\n";
print Bar->can('foo')//'undef', "\n";
print Bar->can('bar')//'undef', "\n";

__END__

CODE(0x1343fa8)
undef
CODE(0x1343fa8)
CODE(0x1343b68)