My munin::snmp_host puppet resource

define 'munin::snmp_host', :plugins, :categories => Puppet::Parser::AST::Leaf::Undef.new({:value => ''}) do
  if @categories != '' then
    create_resource 'munin::node', @name, :categories => @categories, :proxied => true
  end
  @plugins.each do |plugin|
    create_resource 'munin::plugin', "snmp_#{@name}_#{plugin}", :target => "snmp__#{plugin}"
  end
end