'Executes a create instance request on GCE and returns the operation.
:returns dict: A GCE operation resource object, suitable for use with
``wait_for_operation``.'

def _execute_create_instance(self, instance_name, image=None, **kwargs):

    if (image is None):
        image = get_latest_gce_image_for_distribution('centos-7', self.compute)
    body = _create_gce_instance_config(instance_name=instance_name, project=self.project, zone=self.zone, image=image, **kwargs)
    return self.compute.instances().insert(project=self.project, zone=self.zone, body=body).execute()
