code: public void reimage(String poolId, String nodeId) {
          reimageWithServiceResponseAsync(poolId, nodeId).toBlocking().single().body();
      }
docs: Reinstalls the operating system on the specified compute node.
  You can reinstall the operating system on a node only if it is in an idle or running state. This API can be invoked only on pools created with the cloud service configuration property.
  
  @param poolId The ID of the pool that contains the compute node.
  @param nodeId The ID of the compute node that you want to restart.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws BatchErrorException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent