code: @BetaApi
    public final Operation deleteInstance(String instance) {
  
      DeleteInstanceHttpRequest request =
          DeleteInstanceHttpRequest.newBuilder().setInstance(instance).build();
      return deleteInstance(request);
    }
docs: Deletes the specified Instance resource. For more information, see Stopping or Deleting an
  Instance.
  
  <p>Sample code:
  
  <pre><code>
  try (InstanceClient instanceClient = InstanceClient.create()) {
  ProjectZoneInstanceName instance = ProjectZoneInstanceName.of("[PROJECT]", "[ZONE]", "[INSTANCE]");
  Operation response = instanceClient.deleteInstance(instance.toString());
  }
  </code></pre>
  
  @param instance Name of the instance resource to delete.
  @throws com.google.api.gax.rpc.ApiException if the remote call fails