Clusterize does not appear to be a finished module.

Looking at the source for Clusterize->addpair shows that it doesn't actually do anything:

sub add_pair {
    my ($self, $key, $digest) = @_;
    return if $self->pair($key);
    $digest = Clusterize::Pattern->text2digest($digest)
        if ref $digest eq 'ARRAY';
    $self->pair($key, $digest);
    for (keys %{$digest}) {
        $self->add_cluster_pair($_, {key => $key, val => $digest->{$_}
+});
    }
}
[download]

Clusterize::Pattern's text2digest($digest) basically returns an empty hash ref {}, therefore all of the string data is lost and nothing gets initialized for your key at all.

As others have said, just state what you'd like to actually do and someone can probably help you, but this module is not going to work