Application Default Credentials provide a simplified way to obtain credentials
for authenticating with Google APIs.
The Application Default Credentials authenticate as the application itself,
which make them great for working with Google Cloud APIs like Storage or
Datastore. They are the recommended form of authentication when building
applications that run on Google Compute Engine or Google App Engine.
Default credentials are provided by the `golang.org/x/oauth2/google` package. To use them, add the following import:
```
import "golang.org/x/oauth2/google"
```
Some credentials types require you to specify scopes, and service entry points may not inject them. If you encounter this situation you may need to specify scopes as follows:
```
import (
"golang.org/x/net/context"
"golang.org/x/oauth2/google"
"google.golang.org/api/compute/v1"
)
func main() {
// Use oauth2.NoContext if there isn't a good context to pass in.