code: @BetaApi
    public final ListRegionDisksPagedResponse listRegionDisks(String region) {
      ListRegionDisksHttpRequest request =
          ListRegionDisksHttpRequest.newBuilder().setRegion(region).build();
      return listRegionDisks(request);
    }
docs: Retrieves the list of persistent disks contained within the specified region.
  
  <p>Sample code:
  
  <pre><code>
  try (RegionDiskClient regionDiskClient = RegionDiskClient.create()) {
  ProjectRegionName region = ProjectRegionName.of("[PROJECT]", "[REGION]");
  for (Disk element : regionDiskClient.listRegionDisks(region.toString()).iterateAll()) {
  // doThingsWith(element);
  }
  }
  </code></pre>
  
  @param region Name of the region for this request.
  @throws com.google.api.gax.rpc.ApiException if the remote call fails