code: @BetaApi
    public final Disk getRegionDisk(String disk) {
  
      GetRegionDiskHttpRequest request = GetRegionDiskHttpRequest.newBuilder().setDisk(disk).build();
      return getRegionDisk(request);
    }
docs: Returns a specified regional persistent disk.
  
  <p>Sample code:
  
  <pre><code>
  try (RegionDiskClient regionDiskClient = RegionDiskClient.create()) {
  ProjectRegionDiskName disk = ProjectRegionDiskName.of("[PROJECT]", "[REGION]", "[DISK]");
  Disk response = regionDiskClient.getRegionDisk(disk.toString());
  }
  </code></pre>
  
  @param disk Name of the regional persistent disk to return.
  @throws com.google.api.gax.rpc.ApiException if the remote call fails