public void unregisterWorkflowDef(String name, Integer version) {
        Validate.notBlank(name, "Workflow name cannot be blank");
        Validate.notNull(version, "Version cannot be null");
        delete("metadata/workflow/{name}/{version}", name, version);
    }
Removes the workflow definition of a workflow from the conductor server. It does not remove
associated workflows. Use with caution.

@param name Name of the workflow to be unregistered.
@param version Version of the workflow definition to be unregistered.
client/src/main/java/com/netflix/conductor/client/http/MetadataClient.java