public static boolean canMakeHostExclusive(NodeType type, boolean allowHostSharing) {
        return type == NodeType.tenant && !allowHostSharing;
    }
Whether it is allowed to take a host not exclusive to anyone, and make it exclusive to an application.
Returns false if {@code makeExclusive} is false, which can be used to guard this feature.
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/NodeCandidate.java