Adding missing doc comments for block storage
diff --git a/openstack/blockstorage/v1/apiversions/results.go b/openstack/blockstorage/v1/apiversions/results.go
index eeff132..c4ac157 100644
--- a/openstack/blockstorage/v1/apiversions/results.go
+++ b/openstack/blockstorage/v1/apiversions/results.go
@@ -44,10 +44,12 @@
 	return resp.Versions, nil
 }
 
+// GetResult represents the result of a get operation.
 type GetResult struct {
 	gophercloud.CommonResult
 }
 
+// Extract is a function that accepts a result and extracts an API version resource.
 func (r GetResult) Extract() (*APIVersion, error) {
 	var resp struct {
 		Version *APIVersion `mapstructure:"version"`