How to define class inheritance with Puppet Ruby DSL

[Ingo Fischer]

I have a module "Ruby":

# init.pp
class ruby {
  package { 'libldap-ruby1.8':
    ensure => 'installed'
  }
}

Then I have a manifest written with Ruby-DSL, which should inherit this module:

# ldap.rb
hostclass 'ruby::ldap' do
  (...)
end

How do I define that ruby::ldap inherits ruby?