thing.groovy

        // Set the resource pool
        ResourcePool rp
        if (build.resourcePool) {
           rp = (ResourcePool) new InventoryNavigator(rootFolder).searchManagedEntity("ResourcePool", build.resourcePool)

            if (rp == null) {
                throw new ProvisioningException(
                    "Could not find the user-provided ResourcePool " +
                    "${build.resourcePool}.")
            }   
        }   
        else {
           rp = (ResourcePool) host.parent.resourcePool
        }