add 'ExtractHeader' method to object storage return types
diff --git a/rackspace/objectstorage/v1/cdncontainers/results.go b/rackspace/objectstorage/v1/cdncontainers/results.go
index 374d884..05367e2 100644
--- a/rackspace/objectstorage/v1/cdncontainers/results.go
+++ b/rackspace/objectstorage/v1/cdncontainers/results.go
@@ -1,8 +1,20 @@
 package cdncontainers
 
-import "github.com/rackspace/gophercloud"
+import (
+	"net/http"
+
+	"github.com/rackspace/gophercloud"
+)
+
+type headerResult struct {
+	gophercloud.Result
+}
+
+func (hr headerResult) ExtractHeader() (http.Header, error) {
+	return hr.Header, hr.Err
+}
 
 // EnableResult represents the result of a get operation.
 type EnableResult struct {
-	gophercloud.Result
+	headerResult
 }