    # File lib/fog/openstack/requests/compute/update_metadata.rb, line 7
            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.json"
              )
            end