code: public final void cancelOperation(String name) {
  
      CancelOperationRequest request = CancelOperationRequest.newBuilder().setName(name).build();
      cancelOperation(request);
    }
docs: Starts asynchronous cancellation on a long-running operation. The server makes a best effort to
  cancel the operation, but success is not guaranteed. If the server doesn't support this method,
  it returns `google.rpc.Code.UNIMPLEMENTED`. Clients can use
  [Operations.GetOperation][google.longrunning.Operations.GetOperation] or other methods to check
  whether the cancellation succeeded or whether the operation completed despite cancellation. On
  successful cancellation, the operation is not deleted; instead, it becomes an operation with an
  [Operation.error][google.longrunning.Operation.error] value with a
  [google.rpc.Status.code][google.rpc.Status.code] of 1, corresponding to `Code.CANCELLED`.
  
  <p>Sample code:
  
  <pre><code>
  try (OperationsClient operationsClient = OperationsClient.create()) {
  String name = "";
  operationsClient.cancelOperation(name);
  }
  </code></pre>
  
  @param name The name of the operation resource to be cancelled.
  @throws com.google.api.gax.rpc.ApiException if the remote call fails