@Override
    public void removeNamespace(String uid) {
        checkArgument(!Strings.isNullOrEmpty(uid), ERR_NULL_NAMESPACE_UID);

        synchronized (this) {
            if (isNamespaceInUse(uid)) {
                final String error = String.format(MSG_NAMESPACE, uid, ERR_IN_USE);
                throw new IllegalStateException(error);
            }
        }

        Namespace namespace = k8sNamespaceStore.removeNamespace(uid);

        if (namespace != null) {
            log.info(String.format(MSG_NAMESPACE,
                    namespace.getMetadata().getName(), MSG_REMOVED));
        }
    }
@Test(expected = IllegalArgumentException.class)
    public void testRemoveNamespaceWithNull() {
        target.removeNamespace(null);
    }