private void assertExtends(Set<HostSpec> extension,
                                   Set<HostSpec> original) {
            for (HostSpec originalHost : original) {
                HostSpec newHost = findHost(originalHost.hostname(), extension);
                org.junit.Assert.assertEquals(newHost.membership(), originalHost.membership());
            }
        }
Returns a host by cluster name and index, or null if there is no host with the given values in this
node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTest.java