code: @SuppressWarnings("WeakerAccess")
    public CreateClusterRequest setStorageType(@Nonnull StorageType storageType) {
      Preconditions.checkNotNull(storageType);
      Preconditions.checkArgument(
          storageType != StorageType.UNRECOGNIZED, "StorageType can't be UNRECOGNIZED");
  
      proto.getClusterBuilder().setDefaultStorageType(storageType.toProto());
      return this;
    }
docs: Sets the type of storage used by this cluster to serve its parent instance's tables. Defaults
  to {@code SSD}.