DuplicateServiceException when switching singleton election policy in a batch

[rhusar@syrah wildfly-11.0.0.Beta1-SNAPSHOT]$ cat a.cli
batch
/subsystem=singleton/singleton-policy=default/election-policy=simple:remove(){allow-resource-service-restart=true}
/subsystem=singleton/singleton-policy=default/election-policy=random:add(){allow-resource-service-restart=true}
run-batch
[rhusar@syrah wildfly-11.0.0.Beta1-SNAPSHOT]$ ./bin/jboss-cli.sh -c --file=a.cli
The batch failed with the following error (you are remaining in the batch editing mode to have a chance to correct the error):
WFLYCTL0062: Composite operation failed and was rolled back. Steps that failed:
Step: step-2
Operation: /subsystem=singleton/singleton-policy=default/election-policy=random:add(){allow-resource-service-restart=true}
Failure: WFLYCTL0158: Operation handler failed: org.jboss.msc.service.DuplicateServiceException: Service org.wildfly.clustering.singleton.policy.election.default is already registered