<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def cancel_operation( self, name, retry=gapic_v1.method.DEFAULT, timeout=gapic_v1.method.DEFAULT ):
 """Starts asynchronous cancellation on a long-running operation. The server makes a best effort to cancel the operation, but success is not guaranteed. Clients can use :meth:`get_operation` or service- specific 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`` value with a ``google.rpc.Status.code`` of ``1``, corresponding to ``Code.CANCELLED``. Example: Args: name (str):
 The name of the operation resource to be cancelled. retry (google.api_core.retry.Retry):
 The retry strategy to use when invoking the RPC. If unspecified, the default retry from the client configuration will be used. If ``None``, then this method will not retry the RPC at all. timeout (float):
 The amount of time in seconds to wait for the RPC to complete. Note that if ``retry`` is used, this timeout applies to each individual attempt and the overall time it takes for this method to complete may be longer. If unspecified, the the default timeout in the client configuration is used. If ``None``, then the RPC method will not time out. Raises: google.api_core.exceptions.MethodNotImplemented: If the server does not support this method. Services are not required to implement this method. google.api_core.exceptions.GoogleAPICallError: If an error occurred while invoking the RPC, the appropriate ``GoogleAPICallError`` subclass will be raised. """

        # Create the request object.
        request = operations_pb2.CancelOperationRequest(name=name)
        self._cancel_operation(request, retry=retry, timeout=timeout)