HostProvisioner createStaticProvisioner(ApplicationPackage applicationPackage,
                                            ApplicationId applicationId,
                                            Provisioned provisioned) {
        Optional<AllocatedHosts> allocatedHosts = applicationPackage.getAllocatedHosts();
        if (hosted && allocatedHosts.isPresent())
            return createStaticProvisionerForHosted(allocatedHosts.get(), createNodeRepositoryProvisioner(applicationId, provisioned).get());
        return DeployState.getDefaultModelHostProvisioner(applicationPackage);
    }
Returns a host provisioner returning the previously allocated hosts if available and when on hosted Vespa,
returns empty otherwise, which may either mean that no hosts are allocated or that we are running
non-hosted and should default to use hosts defined in the application package, depending on context
configserver/src/main/java/com/yahoo/vespa/config/server/modelfactory/ModelsBuilder.java