data_validator.pl

#!/usr/bin/env perl

use strict;
use warnings;
use utf8;
use feature qw/state say/;
use Data::Validator;

package Foo {
    sub build {
        state $rule = Data::Validator->new(
            item => {isa => 'Bar|Buz'},
        )->with('Method');
        my ($class, $argument) = $rule->validate(@_);

        say 'OK';
    }
}

package Bar {
    sub new {
        bless {}, $_[0];
    }
}

package Buz {
    sub new {
        bless {}, $_[0];
    }
}

Foo->build({item => Bar->new});