Imports golang.org/x/net/context golang.org/x/oauth2 golang.org/x/oauth2/google google.golang.org/api/googleapi google.golang.org/api/storage/v1 upspin.io/cloud/storage upspin.io/errors upspin.io/log upspin.io/upspin Standard library imports bytes encoding/base64 io/ioutil net/http strings time