packages.pm

package X;

# some non-moose abstract class
# there are lots of code using its subclasses

sub write {
    die 'not implemented';
}

package X::Role::Moose;

# so I want to replace it with...

requires 'write';

around ['does', 'isa'] => sub {
    my $orig = shift;
    my $self = shift;
    return 1 if $_[0] eq 'X';
    return $self->$orig(@_);
};