private void validateUsingGoogle(String cloud) {
    if (!cloud.equals(GOOGLE_CLOUD_NAME)) {
      throw new IllegalStateException(
          "Injecting Google objects when cloud != Google! (cloud was " + cloud);
    }
  }
Validate we are using Google Cloud. Should be called in all Providers in this module.

<p>This allows us to install this module and rely on Guice-ified flag parsing, and not do a
separate parse to conditionally install this module.

<p>TODO: Can this be removed? In the new modular structure, will this code only be run/loaded
for Google cloud?
extensions/cloud/portability-cloud-google/src/main/java/org/datatransferproject/cloud/google/GoogleCloudExtensionModule.java