# File lib/fog/compute/openstack/requests/update_metadata.rb, line 5
        def update_metadata(collection_name, parent_id, metadata = {})
          request(
            :body    => Fog::JSON.encode('metadata' => metadata),
            :expects => 200,
            :method  => 'POST',
            :path    => "#{collection_name}/#{parent_id}/metadata"
          )
        end